Compositions and methods for increasing energy metabolism

ABSTRACT

Compositions and methods useful for inducing an increase in fatty acid oxidation or mitochondrial biogenesis, reducing weight gain, inducing weight loss, or increasing Sirt1, Sirt3, or AMPK activity are provided herein. Such compositions comprise a combination of a PDE 5 inhibitor, such as sildenafil or icariin, and resveratrol, and a branched amino acid such as leucine, or its metabolite.

CROSS-REFERENCE

This application claims benefit of priority to U.S. ProvisionalApplication No. 61/726,006, filed Nov. 13, 2012, which is incorporatedherein by reference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

All organisms have developed exquisite metabolic pathways that maintainenergy homeostasis by balancing their intake and metabolism of energywith their expenditure needs of the organism. In mammals, these pathwaysregulate food intake, glucose homeostasis, storage of energy in fatand/or muscle, and mobilization of energy by, for instance, physicalactivity. Malfunctioning of these pathways, often resulting from excessenergy intake relative to energy expenditure, leads to imbalanced energyhomeostasis, which in turn can lead to a wide range of metabolicdisorders. Amongst them are obesity, diabetes, hypertension,arteriosclerosis, high cholesterol, and hyperlipidemia.

The high incidence of metabolic disorders in humans and the relatedimpact on health and mortality presents a significant burden to publichealth. For instance, obesity, clinically defined as a body mass indexof over 30 kg/m2, is estimated to affect 35.7% of the U.S. adultpopulation. Obesity increases the likelihood of many diseases, such asheart disease and type II diabetes, and obesity is one of the leadingpreventable causes of death worldwide. In the U.S., obesity is estimatedto cause roughly 110,000-365,000 deaths per year. Diabetes is ametabolic disorder characterized by high blood glucose levels or lowglucose tolerance, and is estimated to affect 8% of the U.S. population.Diabetes is also significantly associated with higher risk of death fromvascular disease, cancer, renal disease, infectious diseases, externalcauses, intentional self-harm, nervous system disorders, and chronicpulmonary disease (N Engl J Med 2011; 364:829-841). Metabolic syndrome,in which subjects present with central obesity and at least two othermetabolic disorders (such as high cholesterol, high blood pressure, ordiabetes), is estimated to affect 25% of the U.S. population.

Sirtuins are highly conserved protein deacetylases and/orADP-ribosyltransferases that have been shown to extend lifespan in lowermodel organisms, such as yeast, C. elegans, and drosophila. In mammals,sirtuins have been shown to act as metabolic sensors, responding toenvironmental signals to coordinate the activity of genes that regulatemultiple energy homeostasis pathways. For example, studies have shownthat sirtuin activation mimics the effects of caloric restriction, anintervention demonstrated to significantly extend lifespan, andactivates genes that improve glucose homeostasis and the conversion offat to energy by fatty acid oxidation.

The sirtuin pathway also includes phosphodiesterases (PDEs). PDEs areenzymes that interact with cyclic adenosine monophosphates (cAMPs) andcyclic guanosine monophosphates (cGMPs). The PDE family of enzymescomprises multiple subclasses, including PDE 1-11 in humans. Inhibitorsof these phosphodiesterases can prevent the inactivation of cAMPs andcGMPs, and can have a variety of different physiological effects. ThePDE inhibitors can be selective, by preferentially inhibiting one PDEsubclass as compared to another subclass, or non-selective, which have asubstantially lower degree of selectivity for individual PDE subclasses.Sildenafil is an example of a selective PDE inhibitor that has shownselective inhibition of PDE 5. Sildenafil is a pharmaceutically activeagent that has been used to treat pulmonary hypertension, erectiledysfunction, and altitude sickness.

Many efforts have been attempted to develop treatments for metabolicdisorders by targeting specific energy metabolism pathways. Theseefforts have resulted in the development of, for example, isoflavones(U.S. Patent Application No. 20110165125), tetrahydrolipstatin (U.S.Pat. No. 6,004,996), and compositions that modulate the SIRT1 and AMPKpathways (U.S. Patent Application Nos. 20100210692, 20100009992,20070244202 and 20080176822). However, these efforts are of limitedsuccess. For instance, use of the SIRT1 activator resveratrol in humansis hampered by its limited bioavailability, necessitating high dosageswhich have raised safety concerns. Thus, there remains a great need fortreatments that can address a wide range of metabolic disorders bysafely regulating metabolic pathways.

SUMMARY OF THE INVENTION

The present invention generally relates to the field of regulation ofenergy metabolism. In some embodiments, the present invention providesfor compositions, methods, and kits for regulating energy metabolismusing PDE inhibitors, such as PDE 5, and branched chain amino acids.

Compositions including PDE inhibitors can be effective for regulatingenergy metabolism because PDEs are components of the sirtuin pathway.Because these PDE inhibitors can have an effect on the sirtuin pathway,compositions including PDE inhibitors, both selective and non-selective,can have beneficial effects on regulating energy metabolism.

The present invention addresses the need for improved compositions andsupplements for regulating energy metabolism. The regulation of energymetabolism can allow for decreases in weight or adipose tissue,increases in fat oxidation or insulin sensitivity, and/or the decreaseof inflammation or oxidative stress. These effects can be by way of anincrease in or regulation of energy metabolism, including cellularmetabolism and mitochondrial biogenesis.

The subject application provides compositions useful for inducing anincrease in fatty acid oxidation and mitochondrial biogenesis in asubject. The compositions also cause activation of Sirt1 and Sirt3,thereby mediating beneficial downstream effects, including preventionand treatment of diabetes, cardiovascular disease and inflammatorydisease. Such compositions contain a PDE inhibitor, including but notlimited to PDE5 inhibitor such as avanafil, iodenafil, mirodenafil,sildenafil, tadalafil, icariin, vardenafil, udenafil, or zaprinst incombination with a branched chain amino acid and/or metabolites thereof(e.g. beta-hydroxymethylbutyrate (HMB), leucine, keto-isocaproic acid(KIC) or combinations of HMB, KIC and/or leucine). The branched chainand amino acid can be leucine and the metabolites can be HMB and KIC.The subject application also provides methods of increasing fatty acidoxidation in a subject comprising the administration of the disclosedcompositions.

One aspect of the invention provides for a composition effective forenhancing energy metabolism comprising: (a) a PDE inhibitor, e.g., aPDE5 inhibitor; and (b) leucine and/or a leucine metabolite. In someembodiments, the composition enhances energy metabolism in the subjectto a greater degree as compared to administering to the subjectcomponent (a) or (b) alone. In some embodiments, the leucine and/orleucine metabolite are present in free amino acid and/or free amino acidmetabolite form. For example, the leucine may be present in a form thatdoes not comprise a peptide bond.

In some embodiments, the enhanced energy metabolism is measured by anincrease in fatty acid oxidation of an adipocyte by at least about 300%,an increase in glucose utilization of an adipocyte by at least 150%, anincrease in glucose utilization of an adipocyte by a change of at least60%, or an increase in mitochondrial biomass by at least about 15%.

In some embodiments, the enhanced energy metabolism is measured by areduction in postprandial blood glucose of at least 20%, a reduction inpostprandial insulin by at least 30%, a reduction in fasting bloodglucose by at least 40%, a reduction in fasting insulin by at least 40%,a reduction in blood glucose response to glucose load by at least 15%, atwo-fold improvement in insulin tolerance results, or a reduction ininflammatory stress by at least 20%. In some embodiments, the bloodglucose response to glucose load is measured by area under a glucosetolerance curve.

In some embodiments, the PDE 5 inhibitor is avanafil, iodenafil,mirodenafil, sildenafil, tadalafil, icariin, vardenafil, udenafil, orzaprinst. In other embodiments, the PDE 5 inhibitor is sildenafil oricariin. In some embodiments, the PDE 5 inhibitor is icariin. In someembodiments, component (b) is HMB. In some embodiments, component (b) isfree leucine. In other embodiments, the composition further comprises anon-selective PDE inhibitor. In other embodiments, the compositionfurther comprises vitamin B6.

In some embodiments, the composition further comprises apharmaceutically active agent. The composition can further comprise twopharmaceutically active agents. One of the two pharmaceutically activeagents can be sildenafil. In some embodiments, the composition isformulated for oral consumption.

The composition can be a unit dosage comprising a sub-therapeutic amountof component (a). The sub-therapeutic amount of component (a) can bebetween about 0.1 and 20 mg of sildenafil. The sub-therapeutic amount ofcomponent (a) can be between about 0.1 and 10 mg of sildenafil. Thesub-therapeutic amount of component (a) can be between about 0.5-50 mgof avanafil, 0.05-10 mg of iodenafil, 0.25-25 mg of mirodenafil,0.01-1.25 mg of tadalafil, 0.01-1.25 mg of vardenafil, 0.5-50 mg ofudenafil, 0.5-50 mg of zaprinst, or 0.05-100 mg of icariin. Component(b) can comprise at least about 500 mg of leucine. Component (b) cancomprise at least about 200 mg of HMB. In some embodiments, component(b) comprises 50-1000 mg of free leucine. Component (b) can comprise500-700 mg of free leucine.

Another aspect of the invention provides for a composition effective forenhancing energy metabolism comprising: (a) a PDE 5 inhibitor; and (b) apolyphenol, wherein the composition enhances energy metabolism in thesubject to a greater degree as compared to administering to the subjectcomponent (a) or (b) alone. The polyphenol can be resveratrol.

The polyphenol can be a stilbene or hydroxycinnamic acid. The polyphenolcan be chlorogenic acid, resveratrol, caffeic acid, piceatannol, ellagicacid, epigallocatechin gallate (EGCG), grape seed extract, or any analogthereof. The composition can further comprise leucine and/or a leucinemetabolite.

One aspect of the invention provides for a method of regulating energymetabolism in a subject in need thereof comprising administering to thesubject a composition described herein. The composition can beadministered orally.

Another aspect of the invention provides for a method of regulatingenergy metabolism comprising identifying a subjecting having or prone toobesity or diabetes, administering to the subject a compositiondescribed herein.

The invention also provides for a method of regulating energy metabolismin a subject in need thereof comprising administering to the subject aunit dosage comprising a subtherapeutic amount of a PDE inhibitor, e.g.,a PDE 5 inhibitor and at least about 500 mg of leucine or 200 mg of HMB.The subtherapeutic amount of the PDE inhibitor, e.g., a PDE 5 inhibitorcan be less than about 10 mg/day. The PDE 5 inhibitor can be sildenafil.The leucine may be in free amino acid form, e.g., intact form. Forexample, the leucine may be present in a form that does not comprise apeptide bond.

One aspect of the invention provides for a method for increasing energymetabolism in a subject comprising: administering a compositiondescribed herein at a selected dosing level, wherein the selected dosinglevel induces a circulating level of about 1 nM sildenafil and about 0.5mM leucine in the subject. The leucine may be in free amino acid form,e.g., intact form. For example, the leucine may be present in a formthat does not comprise a peptide bond. In some cases, any of the methodsherein comprise administering the composition for over 1 week, for over2 weeks, or for over 6 weeks.

The invention also provides a method of treating diabetes in a subjectin need thereof, comprising administering to the subject atherapeutically effective composition comprising a PDE 5 inhibitor; anda branched-chain amino acid in free amino acid form or a metabolitethereof. The diabetes may be, e.g., Type I diabetes or Type II diabetes.For example, administration of the composition can improve insulinsensitivity in a subject. Type I diabetes may be characterized byreduced ability to produce insulin as compared to a subject without TypeI diabetes. Administration of a composition described herein can improvethe sensitivity of a subject with Type I diabetes to the insulin that isproduced by or administered to the subject. The improved sensitivity canbe greater than the sensitivity of the subject as measured beforeadministration of the composition. Type II diabetes may be characterizedby reduced sensitivity to insulin. Accordingly, administration of acomposition described herein can improve insulin sensitivity in asubject with Type II diabetes. The diabetes may be a diet-induceddiabetes. In some embodiments, the branched chain amino acid is freeleucine. In some embodiments, the branched chain amino acid metaboliteis HMB. It is understood that the therapeutically effective compositioncan be any of the compositions described herein.

In some embodiments, the PDE5 inhibitor is icariin. In some embodiments,the PDE5 inhibitor is sildenafil. In some embodiments, the PDE5inhibitor is tadalafil. In some embodiments, the PDE5 inhibitor isvardenafil. In some embodiments, the PDE5 inhibitor is udenafil. In someembodiments, the PDE5 inhibitor is zaprinst.

In some embodiments, the method comprises administering thetherapeutically effective composition orally. In some embodiments, themethod comprises administering the therapeutically effective compositionfor at least one week. In some embodiments, the method comprisesadministering the therapeutically effective composition for at least twoweeks. In some embodiments, the method comprises administering thetherapeutically effective composition for at least six weeks.

In some embodiments, administering the therapeutically effectivecomposition improves a symptom of diabetes in the subject. The symptomof diabetes can be a symptom of Type I and/or Type II Diabetes. Theimprovement of the diabetes symptom can be measured by a reduction inpostprandial blood glucose of at least 20%, a reduction in postprandialinsulin by at least 30%, a reduction in fasting blood glucose by atleast 40%, a reduction in fasting insulin by at least 40%, a reductionin blood glucose response to a glucose load by at least 15%, a two-foldimprovement in insulin tolerance results, or a reduction in inflammatorystress by at least 20%. In some embodiments, the blood glucose responseto glucose load is measured by area under a glucose tolerance curve.

Another aspect of the invention provides for a kit comprising amulti-day supply of unit dosages of a composition described herein andinstructions directing the administration of said multi-day supply overa period of multiple days. In some embodiments, the kit furthercomprises a wearable activity monitor.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawing(s) of which:

FIG. 1 depicts a diagram showing a sirtuin pathway.

FIG. 2 shows the interactive effects of sildenafil with HMB, leucine andresveratrol on fatty acid oxidation in C2C12 myotubes. Fatty acidoxidation was measured as O₂ consumption response to palmitate injectionand is expressed as % change from pre-injection baseline. The verticalline shows the time of palmitate injection; data points to the left ofthis line are baseline measurements and those to the right of the lineshow the O₂ consumption response.

FIG. 3 shows the interactive effects of sildenafil with HMB, leucine andresveratrol on fatty acid oxidation in C2C12 myotubes. Data expressed as% change from control value. *p=0.013; **p=0.015.

FIG. 4 shows the interactive effects of sildenafil with HMB, leucine andresveratrol on fatty acid oxidation in 3T3-L1 adipocytes. Data expressedas % change from control value.*p<0.05.

FIG. 5 shows the interactive effects of sildenafil with HMB, leucine andresveratrol on glucose utilization in C2C12 myotubes. Glucoseutilization was measured as extracellular acidification response toglucose injection. *p=0.04.

FIG. 6 shows the interactive effects of sildenafil with HMB, leucine andresveratrol on glucose utilization in 3T3-L1 adipocytes. Glucoseutilization was measured as extracellular acidification response toglucose injection. *p=0.05.

FIG. 7 shows the interactive effects of icariin with HMB, leucine andresveratrol on fatty acid oxidation in C2C12 myotubes. Fatty acidoxidation was measured as O₂ consumption response to palmitate injectionand is expressed as % change from pre-injection baseline. The verticalline shows the time of palmitate injection; data points to the left ofthis line are baseline measurements and those to the right of the lineshow the O₂ consumption response.

FIG. 8 shows the interactive effects of icariin with HMB, leucine andresveratrol on fatty acid oxidation in C2C12 myotubes. Data expressed as% change from control value. *p=0.03; **p=0.002.

FIG. 9 shows the interactive effects of icariin with HMB, leucine andresveratrol on fatty acid oxidation in 3T3-L1 adipocytes. Data expressedas % change from control value. *p<0.05.

FIG. 10 shows the interactive effects of sildenafil with HMB, leucineand resveratrol on nitric oxide production in C2C12 myotubes. *p<0.0001vs. control; **p=0.0003 vs. all other treatments.

FIG. 11 shows the interactive effects of icariin with HMB, leucine andresveratrol on nitric oxide production in C2C12 myotubes. p<0.0001 vs.control; **p=0.00013 vs. all other treatments.

FIG. 12 shows the interactive effects of sildenafil with HMB, leucineand resveratrol on mitochondrial biogenesis, measured as mitochondrialmass, in C2C12 myotubes. *p<0.0001 vs. control; **p=0.0003 vs. all othertreatments.

FIG. 13 shows the interactive effects of icariin (1 nM) with HMB (5 μM),leucine and resveratrol on mitochondrial biogenesis, measured asmitochondrial mass, in C2C12 myotubes. p<0.0001 vs. control; **p=0.00013vs. all other treatments.

FIG. 14 shows results from an intraperitoneal glucose tolerance test inmice following six weeks on low or high fat diet.

FIG. 15 shows effects of seven days of leucine or leucine+icariintreatment on post-prandial blood glucose levels in high fat diet mice,as compared to untreated low fat diet mice.

FIG. 16 shows effects of fourteen days of leucine or leucine+icariintreatment on post-prandial blood glucose levels in high fat diet mice,as compared to untreated low fat diet mice.

FIG. 17 shows effects of fourteen days of leucine or leucine+icariintreatment on post-prandial plasma insulin in high fat diet mice, ascompared to untreated low fat diet mice.

FIG. 18 show effects of fourteen days of leucine or leucine+icariintreatment on homeostatic assessment of insulin resistance measures inhigh fat diet mice, as compared to untreated low fat diet mice.

FIG. 19 shows blood glucose response to 1.2 U insulin/kg body weightfollowing 28 days of leucine or leucine+icariin treatment in high fatdiet mice, as compared to untreated low fat diet mice.

FIG. 20 shows the 30-minute blood glucose response to 1.2 U insulin/kgbody weight following 28 days of leucine or leucine+icariin treatment inhigh fat diet mice, as compared to untreated low fat diet mice.

FIG. 21 shows results from a glucose tolerance test measured at 5 weeksof treatment with leucine or leucine+icariin in high fat diet mice, ascompared to untreated low fat diet mice.

FIG. 22 shows the calculated integrated blood glucose response toglucose load over time obtained from the glucose tolerance test depictedin FIG. 21.

FIG. 23 shows fasting blood glucose levels following 6 weeks oftreatment with leucine or leucine+icariin in high fat diet mice, ascompared to untreated low fat diet mice.

FIG. 24 shows fasting insulin levels following 6 weeks of treatment withleucine or leucine+icariin in high fat diet mice, as compared tountreated low fat diet mice.

FIG. 25 shows Homeostatic Assessment of Insulin Resistance following 6weeks of treatment with leucine or leucine+icariin in high fat dietmice, as compared to untreated low fat diet mice.

FIG. 26 shows liver mass following 6 weeks of treatment with leucine orleucine+icariin in high fat diet mice, as compared to untreated low fatdiet mice.

FIG. 27 shows levels of the inflammatory marker C-reactive proteinfollowing 6 weeks of treatment with leucine or leucine+icariin in highfat diet mice, as compared to untreated low fat diet mice.

DETAILED DESCRIPTION OF THE INVENTION

Several aspects of the invention are described below with reference toexample applications for illustration. It should be understood thatnumerous specific details, relationships, and methods are set forth toprovide a full understanding of the invention. One having ordinary skillin the relevant art, however, will readily recognize that the inventioncan be practiced without one or more of the specific details or withother methods. Unless stated otherwise, the present invention is notlimited by the illustrated ordering of acts or events, as some acts mayoccur in different orders and/or concurrently with other acts or events.Furthermore, not all illustrated acts or events are required toimplement a methodology in accordance with the present invention. Theconcentration of various components in the disclosed compositions areexemplary and not meant to be limited to the recited concentration perse.

As used herein, the term “subject” or “individual” includes mammals.Non-limiting examples of mammals include humans and mice, includingtransgenic and non-transgenic mice. The methods described herein can beuseful in both human therapeutics, pre-clinical, and veterinaryapplications. In some embodiments, the subject is a mammal, and in someembodiments, the subject is human. Other mammals include, and are notlimited to, apes, chimpanzees, orangutans, monkeys; domesticated animals(pets) such as dogs, cats, guinea pigs, hamsters, mice, rats, rabbits,and ferrets; domesticated farm animals such as cows, buffalo, bison,horses, donkey, swine, sheep, and goats; or exotic animals typicallyfound in zoos, such as bear, lions, tigers, panthers, elephants,hippopotamus, rhinoceros, giraffes, antelopes, sloth, gazelles, zebras,wildebeests, prairie dogs, koala bears, kangaroo, pandas, giant pandas,hyena, seals, sea lions, and elephant seals.

The terms “administer”, “administered”, “administers” and“administering” are defined as the providing a composition to a subjectvia a route known in the art, including but not limited to intravenous,intraarterial, oral, parenteral, buccal, topical, transdermal, rectal,intramuscular, subcutaneous, intraosseous, transmucosal, orintraperitoneal routes of administration. In certain embodiments of thesubject application, oral routes of administering a composition may bepreferred.

As used herein, “agent” or “biologically active agent” refers to abiological, pharmaceutical, or chemical compound or other moiety.Non-limiting examples include simple or complex organic or inorganicmolecule, a peptide, a protein, a peptide nucleic acid (PNA), anoligonucleotide (including e.g., aptomer and polynucleotides), anantibody, an antibody derivative, antibody fragment, a vitaminderivative, a carbohydrate, a toxin, or a chemotherapeutic compound.Various compounds can be synthesized, for example, small molecules andoligomers (e.g., oligopeptides and oligonucleotides), and syntheticorganic compounds based on various core structures. In addition, variousnatural sources can provide compounds for screening, such as plant oranimal extracts, and the like. A skilled artisan can readily recognizethat there is no limit as to the structural nature of the agents of thepresent invention.

The term “effective amount” or “therapeutically effective amount” refersto that amount of a compound described herein that is sufficient toeffect the intended application including but not limited to diseasetreatment, as defined below. The therapeutically effective amount mayvary depending upon the intended application (in vitro or in vivo), orthe subject and disease condition being treated, e.g., the weight andage of the subject, the severity of the disease condition, the manner ofadministration and the like, which can readily be determined by one ofordinary skill in the art. The term also applies to a dose that willinduce a particular response in target cells, e.g., reduction ofproliferation or down regulation of activity of a target protein. Thespecific dose will vary depending on the particular compounds chosen,the dosing regimen to be followed, whether it is administered incombination with other compounds, timing of administration, the tissueto which it is administered, and the physical delivery system in whichit is carried.

The term “energy metabolism,” as used herein, refers to thetransformation of energy that accompanies biochemical reactions in thebody, including cellular metabolism and mitochondrial biogenesis. Energymetabolism can be quantified using the various measurements describedherein, for example and without limitations, weight-loss, fat-loss,insulin sensitivity, fatty acid oxidation, glucose utilization,triglyceride content, Sirt 1 expression level, AMPK expression level,oxidative stress, and mitochondrial biomass.

The term “isolated”, as applied to the subject components, for example aPDE 5 inhibitor, including but not limited to sildenafil and icariin,leucine and leucine metabolites (such as HMB), and resveratrol, refersto a preparation of the substance devoid of at least some of the othercomponents that may also be present where the substance or a similarsubstance naturally occurs or is initially obtained from. Thus, forexample, an isolated substance may be prepared by using a purificationtechnique to enrich it from a source mixture. Enrichment can be measuredon an absolute basis, such as weight per volume of solution, or it canbe measured in relation to a second, potentially interfering substancepresent in the source mixture. Increasing enrichment of the embodimentsof this invention are increasingly more preferred. Thus, for example, a2-fold enrichment is preferred, 10-fold enrichment is more preferred,100-fold enrichment is more preferred, 1000-fold enrichment is even morepreferred. A substance can also be provided in an isolated state by aprocess of artificial assembly, such as by chemical synthesis.

A “modulator” of a pathway refers to a substance or agent whichmodulates the activity of one or more cellular proteins mapped to thesame specific signal transduction pathway. A modulator may augment orsuppress the activity and/or expression level or pattern of a signalingmolecule. A modulator can activate a component in a pathway by directlybinding to the component. A modulator can also indirectly activate acomponent in a pathway by interacting with one or more associatedcomponents. The output of the pathway can be measured in terms of theexpression or activity level of proteins. The expression level of aprotein in a pathway can be reflected by levels of corresponding mRNA orrelated transcription factors as well as the level of the protein in asubcellular location. For instance, certain proteins are activated bytranslocating in or out of a specific subcellular component, includingbut not limited to nucleus, mitochondria, endosome, lysosome or othermembraneous structure of a cell. The output of the pathway can also bemeasured in terms of physiological effects, such as mitochondrialbiogenesis, fatty acid oxidation, or glucose uptake.

An “activator” refers to a modulator that influences a pathway in amanner that increases the pathway output. Activation of a particulartarget may be direct (e.g. by interaction with the target) or indirect(e.g. by interaction with a protein upstream of the target in asignaling pathway including the target).

The term “selective inhibition” or “selectively inhibit” as referred toa biologically active agent refers to the agent's ability topreferentially reduce the target signaling activity as compared tooff-target signaling activity, via direct or interact interaction withthe target.

A “suppressor” can be a modulator that influences a pathway in a mannerthat decreases pathway output.

The term “substantially free”, as used herein, refers to compositionsthat have less than about 10%, less than about 5%, less than about 1%,less than about 0.5%, less than 0.1% or even less of a specifiedcomponent. For example a composition that is substantially free ofnon-branched chain amino acids may have less than about 1% of thenon-branched chain amino acid lysine. For example, substantially free ofa non-branched chain amino acid can be evidenced by less than 1% of thenon-branched chain amino acid when compared to the rest of the aminoacids is a given composition.

A “sub-therapeutic amount” of an agent, an activator or a therapy is anamount less than the effective amount for that agent, activator ortherapy, but when combined with an effective or sub-therapeutic amountof another agent or therapy can produce a desired result, due to, forexample, synergy in the resulting efficacious effects, and/or reducedside effects.

A “synergistic” or “synergizing” effect can be such that the one or moreeffects of the combination compositions are greater than the one or moreeffects of each component alone at a comparable dosing level, or theycan be greater than the predicted sum of the effects of all of thecomponents at a comparable dosing level, assuming that each componentacts independently. The synergistic effect can be about, or greater thanabout 10, 20, 30, 50, 75, 100, 110, 120, 150, 200, 250, 350, or 500% oreven more than the effect on a subject with one of the components alone,or the additive effects as measured when each of the components whenadministered individually. The effect can be any of the measurableeffects described herein.

The terms “free amino acid form” or “individual amino acid form”, asused herein, can refer to amino acids that are not bound to other aminoacids, for example, by peptide bonds. For example, “free” or“individual” leucine refers to leucine not bound to other amino acids bypeptide bonds.

Compositions

The subject compositions can include selective phosphodiesterase (PDE)inhibitors. The PDE inhibitors can have a selectivity against one ormore PDE enzymes or targets. For example, the PDE inhibitors can be aPDE 1, 2, 3, 4, 5, 6, 9, or 11 selective inhibitor. The sirtuin pathwayincludes, without limitation, signaling molecules such as, Sirt1, Sirt3,and AMPK. The PDE inhibitor can be combined with another component thatprovides for a synergistic effect, for example, the PDE inhibitor can becombined with leucine and/or metabolites thereof. In some embodiments,the compositions can include a PDE 5 inhibitor, such as sildenafil oricariin, and leucine and/or a metabolite thereof, such ashydroxymethylbutyrate (HMB).

The invention provides for compositions that can increase or modulatethe output of a sirtuin pathway. The output of the pathway can bedetermined by the expression level and/or the activity of the pathwayand/or a physiological effect. In some embodiments, activation of theSirt1 pathway includes stimulation of PGC1-α and/or subsequentstimulation of mitochondrial biogenesis and fatty acid oxidation. Ingeneral, a sirtuin pathway activator is compound that activates orincreases one or more components of a sirtuin pathway. An increase oractivation of a sirtuin pathway can be observed by an increase in theactivity of a pathway component protein. For example, the protein can beSirt1, PGC1-α, AMPK, Epac1, Adenylyl cyclase, Sirt3, or any otherproteins and their respective associated proteins along the signalingpathway depicted in FIG. 1 (Park et. al., “Resveratrol AmelioratesAging-Related Metabolic Phenotypes by Inhibiting cAMPPhosphodiesterases,” Cell 148, 421-433 Feb. 3, 2012). Non-limitingexamples of physiological effects that can serve as measures of sirtuinpathway output include mitochondrial biogenesis, mitochondrial biomass,fatty acid oxidation, glucose uptake, nitric oxide production, palmitateuptake, oxygen consumption, carbon dioxide production, weight loss, heatproduction, visceral adipose tissue loss, respiratory exchange ratio,insulin sensitivity, inflammation marker level, vasodilation, browningof fat cells, and irisin production. Examples of indicia of browning offat cells include, without limitation, increased fatty acid oxidation,and expression of one or more brown-fat-selective genes (e.g. Ucp1,Cidea, Prdm16, and Ndufs1). In some embodiments, changes in one or morephysiological effects that can serve as measures of sirtuin pathwayoutput are induced by increasing irisin production, such as byadministering a composition of the invention.

An increase in mitochondrial biogenesis can be evidenced by an increasein the formation of new mitochondria, an increase in mitochondrialbiomass and/or by an increase in mitochondrial functions, such asincreased fatty acid oxidation, increased heat generation, increasedinsulin sensitivity, increased in glucose uptake, increased invasodilation, decreased in weight, decreased in adipose volume, anddecreased inflammatory response or markers in a subject.

The compositions can be combination compositions which may include oneor more synergistic components. The composition comprising a pluralityof components can be such that the synergistic effect is an enhancementin cellular metabolism, and that cellular metabolism is increased to agreater degree as compared to the sum of the effects of administeringeach component, determined as if each component exerted its effectindependently, also referred to as the predicted additive effect herein.For example, if a composition comprising component (a) yields an effectof a 20% improvement in cellular metabolism and a composition comprisingcomponent (b) yields an effect of 50% improvement in cellularcomposition, then a composition comprising both component (a) andcomponent (b) would have a synergistic effect if the combinationcomposition's effect on cellular metabolism is greater than 70%.

A synergistic combination composition can have an effect that is greaterthan the predicted additive effect of administering each component ofthe combination composition alone as if each component exerted itseffect independently. For example, if the predicted additive effect is70%, an actual effect of 140% is 70% greater than the predicted additiveeffect or is 1 fold greater than the predicted additive effect. Thesynergistic effect can be at least about 20, 50, 75, 90, 100, 150, 200or 300% greater than the predicted additive effect. Alternatively, thesynergistic effect can be at least about 0.2, 0.5, 0.9, 1.1, 1.5, 1.7,2, or 3 fold greater than the predicted additive effect.

In some embodiments, the synergistic effect of the combinationcompositions can allow for reduced dosing amounts, leading to reducedside effects to the subject and reduced cost of treatment. In otherembodiments, the synergistic effect can allow for results that are notachievable through any other conventional treatments. The subjectcombination compositions provide a significant improvement in theregulation of energy metabolism.

In some embodiments, the compositions can be combination compositions ofone or more branched chain amino acids and/or metabolites thereof and asirtuin-pathway activator can have one or more characteristics. The oneor more branched amino acids may be in free amino acid form. Thecombination compositions (a) can have a synergistic effect in increasingthe sirtuin-pathway output, (b) increase sirtuin-pathway output by atleast about 1, 2, 5, 7, 10, or 20 fold, (c) have a molar ratio ofbranched chain amino acids and/or metabolites thereof to sirtuin-pathwayoutput that is greater than about 20, (d) be formulated as a unit dosagefor oral ingestion, where the sirtuin-pathway activator is asubstantially homogeneous population of polyphenol molecules, and (e)can have a synergistic effect and further comprise a food carrier. Anyof the compositions described herein can have one or more of thesecharacteristics. Examples of sirtuin-pathway activators used incombination with one more branched chain amino acids are described inU.S. patent application Ser. Nos. 13/549,381 and 13/549,399, which areeach incorporated by referenced in their entirety.

In some embodiments, the present invention provides a compositioncomprising (a) one or more types of branched amino acids and/ormetabolites thereof and (b) a selective PDE inhibitor present in asub-therapeutic amount, wherein the composition is synergisticallyeffective in increasing the sirtuin-pathway output by at least about 5,10, 50, 100, 200, 500 or more fold as compared to that of component (a)or (b) when used alone. Branched chain amino acids in the compositionmay be in free amino acid form.

Phosphodiesterase Inhibitors

In some embodiments, the sirtuin pathway activator modulates theactivity of phosphodiesterase (PDE). The sirtuin pathway activator canmodulate the activity of PDE as a PDE inhibitor. The PDE inhibitor canbe selective or non-selective. The PDE inhibitor can exhibit selectiveinhibition to a PDE subclass, for example PDE 5. Examples of selectivePDE inhibitors include inhibitors to PDE 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,or 11. A non-selective PDE inhibitor can be one that does notdistinguish among sub-classes of phosphodiesterases. In addition, somenon-selective PDE inhibitors may interact with more than one metabolicpathway. For examine, some non-selective PDE inhibitors may be xanthinederivatives and serve as adenosine antagonists and have unknowninteractions with other metabolic pathways. Selective PDE inhibitors canbe PDE inhibitors that exhibit preferential interaction with a selectedPDE. For example, a PDE inhibitor can have a strong interaction with PDE5, and very little interaction with other PDE sub-classes.

Any agents that selectively and negatively regulate a PDE subclass, suchas PDE 5, expression or activity can be used as selective PDE inhibitorsin the compositions and methods of the invention.

For example, a selective PDE inhibitor alternatively can be an agentthat exhibits a 50% inhibitory concentration (IC50) with respect to aPDE subclass, such as PDE 5, that is at least at least 10-fold, at least20-fold, at least 50-fold, at least 100-fold, at least 1000-fold, atleast 10,000-fold lower than the inhibitor's IC50 with respect to one,two, three, or more other PDE subclasses. In some embodiment, aselective PDE inhibitor can be an agent that exhibits a 50% inhibitoryconcentration (IC50) with respect to a PDE subclass, such as PDE 5, thatis at least at least 10-fold, at least 20-fold, at least 50-fold, atleast 100-fold, at least 1000-fold, at least 10,000-fold, or more, lowerthan the inhibitor's IC50 with respect to all other PDE subclasses.

In one aspect, IC50 is a determination of the concentration at which 50%of a given PDE is inhibited in a cell-based assay. IC50 determinationscan be accomplished using any conventional techniques known in the art.In general, an IC50 can be determined by measuring the activity of agiven enzyme in the presence of a range of concentrations of theinhibitor under study. The experimentally obtained values of enzymeactivity then are plotted against the inhibitor concentrations used. Theconcentration of the inhibitor that shows 50% enzyme activity (ascompared to the activity in the absence of any inhibitor) is taken asthe “IC50” value. Analogously, other inhibitory concentrations can bedefined through appropriate determinations of activity. For example, insome settings it can be desirable to establish a 90% inhibitoryconcentration, i.e., IC90, etc.

Methods for measuring selectivity of PDE inhibitors are described in“Phosphodiesterase-5 Gln-817 is critical for cGMP, vardenafil, orsildenafil affinity: its orientation impacts cGMP but not cAMP affinity”by Zoraghi (2006) and “Cyclic Nucleotide Phosphodiesterases: MolecularRegulation to Clinical Use” by Bender (2006) which are incorporatedherein in its entirety by reference.

The subject biologically active agent may inhibit PDE activity with anIC50 value of about 100 nM or less, preferably about 50 nM, about 25 nM,about 10 nM, about 5 nM, about 1 nM, 100 pM, 50 pM, 25 pM, 10 pM, 1 pM,or less, as ascertained in a cell-based assay or an in vitro kinaseassay.

In some embodiments, the sirtuin pathway activator is a PDE 1 inhibitorsuch as nimodipine, vinopocetine, and IC224. The PDE 1 inhibitor caninteract with PDE 1, which is a Ca2+/calmodulin-regulatedphosphodiesterase that serves to degrade both cAMP and cGMP. Thevinopocetine can be derived from periwinkle extract, and it can serve asa cerebrovascularvasodilator. Vinopocetine can be in the form of adietary supplement.

In other embodiments, the sirtuin pathway activator is a PDE 3 inhibitorsuch as meribendan, arinone and cilostamide. The sirtuin pathwayactivator can be a PDE 4 inhibitor, such as apremilast, mesembrine,ibudilast, piclamilast, luteolin, roflumilast, cilomilast, diazepam,rolipram and YM796. The sirtuin pathway activator can be a PDE 4inhibitor, such as rolipram and YM796. The PDE 4 inhibitor can interactwith PDE 4, which is a cAMP-specific phosphodiesterase that predominatesin immune cells.

In some embodiments, the sirtuin pathway activator is a PDE 5 inhibitorsuch as avanafil, iodenafil, mirodenafil, sildenafil, tadalafil,icariin, vardenafil, udenafil, or zaprinst. In other embodiments thesirtuin pathway activator is sildenafil or icariin. The PDE 5 inhibitorcan interact with PDE 5, which is a cGMP-specific PDE. Increases in cGMPsignaling can increase mitochondrial biogenesis both in vitro and invivo. A PDE 5 inhibitor can increase nitric oxide signaling and be aneffective vasodilator. Examples of PDE 5 inhibitors are described inU.S. Pat. Nos. 5,250,534 and 6,469,012, which are each incorporated byreference in their entirety.

In some embodiments, the sirtuin pathway activator can be a selectivePDE inhibitor. In other embodiments, the sirtuin pathway activator is anon-selective PDE inhibitor. PDE inhibitors can be naturally occurringor non-naturally occurring (e.g. manufactured), and may be provided inthe form of a natural source comprising the PDE inhibitor, or an extractthereof (e.g. purified). Examples of non-selective PDE inhibitorsinclude, but are not limited to, caffeine, theophylline, theobromine,3-isobutyl-1-methylxanthine (IBMX), pentoxifylline(3,7-dihydro-3,7-dimethyl-1-(5oxohexyl)-1H-purine-2,6-dione),aminophylline, paraxanthine, and salts, derivatives, metabolites,catabolites, anabolites, precursors, and analogs thereof. Non-limitingexamples of natural sources of PDE inhibitors include coffee, tea,guarana, yerba mate, cocoa, and chocolate (e.g. dark chocolate).

Additional Sirtuin Pathway Activators

In some embodiments, a polyphenol, such as resveratrol, or anothersirtuin pathway activator is administered in place of or in addition toa PDE-5 inhibitor. In some embodiments, compositions comprising one ormore components described herein comprise a PDE inhibitor in place of orin addition to resveratrol or other sirtuin pathway activator.Typically, a PDE inhibitor is provided in an amount that is synergisticwith one or more other components of a composition or method oftreatment.

The polyphenol can be a stilbene or a hydroxycinnamic acid. In someembodiments, the sirtuin-pathway activator or AMPK pathway activator canbe a polyphenol. For example, the polyphenol can be chlorogenic acid,resveratrol, caffeic acid, piceatannol, ellagic acid, epigallocatechingallate (EGCG), grape seed extract, or any analog thereof. In someembodiments, the activator can be resveratrol, an analog thereof, or ametabolite thereof. For example, the activator can be pterostilbene or asmall molecule analog of resveratrol. Examples of small molecule analogsof resveratrol are described in U.S. Patent Application Nos.20070014833, 20090163476, and 20090105246, which are incorporated hereinby reference in its entirety.

The polyphenol can be a substantially homogeneous population ofpolyphenols. The polyphenol can be one type of polyphenol, wherein thecomposition can exclude all other types of polyphenols. In otherembodiments, the composition can comprise two, three, or four types ofpolyphenols, and exclude all other types of polyphenols. In someembodiments, the composition can comprise 1, 2, 3, or 4 types ofpolyphenols and less than 0.1, 0.5, 1, or 2% of any other types ofpolyphenols.

In various other embodiments, compositions are formulated such that theydo not contain (or exclude) one or more of the following ingredients:caffeine, green tea extract or extracts from guarana seed or guaranaplants.

In other embodiments, the sirtuin-pathway activator or AMPK pathwayactivator can be irisin, quinic acid, cinnamic acid, ferulic acid,fucoxanthin, a biguanide (such as metformin), rosiglitazone, or anyanalog thereof. Alternatively the sirtuin-pathway activator or AMPKpathway activator can be isoflavones, pyroloquinoline (PQQ), quercetin,L-carnitine, lipoic acid, coenzyme Q10, pyruvate,5-aminoimidazole-4-carboxamide ribotide (ALCAR), bezfibrate, oltipraz,and/or genistein. In some embodiments, the sirtuin pathway activator isa PDE inhibitor.

In some embodiments, the composition can comprise a selective PDE-5inhibitor in combination of one or more the following: metformin,resveratrol, and a branched chain amino acid or metabolite thereof (e.g.level of HMB).

In some embodiments, the composition can comprise synergisticcombinations of sirtuin pathway activators. For example, a compositioncan comprise synergistic amounts of metformin and a PDE inhibitor. Insome embodiments, the composition comprises metformin and caffeine.

In some embodiments, the sirtuin-pathway activator that can be combinedwith a PDE-5 inhibitor include an agent that stimulates the expressionof the Fndc5, PGC1-α, or UCP1. The expression can be measured in termsof the gene or protein expression level. Alternatively, the sirtuinpathway activator can be irisin. Methods for increasing the level ofirisin are described in Bostrom et al., “A PGC1-α-dependent myokine thatdrives brown-fat-like development of white fat and thermogenesis,”Nature, Jan. 11, 2012.

In some embodiments, the sirtuin-pathway activator that can be socombined is a flavones or chalcone. In one embodiment, exemplary sirtuinactivators are those described in Howitz et al. (2003) Nature 425: 191and include, for example, resveratrol(3,5,4′-Trihydroxy-trans-stilbene), butein(3,4,2′,4′-Tetrahydroxychalcone), piceatannol(3,5,3′,4′-Tetrahydroxy-trans-stilbene), isoliquiritigenin(4,2′,4′-Trihydroxychalcone), fisetin (3,7,3′,4′-Tetrahyddroxyflavone),quercetin (3,5,7,3′,4′-Pentahydroxyflavone), Deoxyrhapontin(3,5-Dihydroxy-4′-methoxystilbene 3-O-β-D-glucoside); trans-Stilbene;Rhapontin (3,3′,5-Trihydroxy-4′-methoxystilbene 3-O-β-D-glucoside);cis-Stilbene; Butein (3,4,2′,4′-Tetrahydroxychalcone);3,4,2′4′6′-Pentahydroxychalcone; Chalcone;7,8,3′,4′-Tetrahydroxyflavone; 3,6,2′,3′-Tetrahydroxyflavone;4′-Hydroxyflavone; 5,4′-Dihydroxyflavone 5,7-Dihydroxyflavone; Morin(3,5,7,2′,4′-Pentahydroxyflavone); Flavone; 5-Hydroxyflavone;(−)-Epicatechin (Hydroxy Sites: 3,5,7,3′,4′); (−)-Catechin (HydroxySites: 3,5,7,3′,4′); (−)-Gallocatechin (Hydroxy Sites: 3,5,7,3′,4′,5′)(+)-Catechin (Hydroxy Sites: 3,5,7,3′,4′);5,7,3′,4′,5′-pentahydroxyflavone; Luteolin(5,7,3′,4′-Tetrahydroxyflavone); 3,6,3′,4′-Tetrahydroxyflavone;7,3′,4′,5′-Tetrahydroxyflavone; Kaempferol(3,5,7,4′-Tetrahydroxyflavone); 6-Hydroxyapigenin(5,6,7,4′-Tetrahydoxyflavone); Scutellarein); Apigenin(5,7,4′-Trihydroxyflavone); 3,6,2′,4′-Tetrahydroxyflavone;7,4′-Dihydroxyflavone; Daidzein (7,4′-Dihydroxyisoflavone); Genistein(5,7,4′-Trihydroxyflavanone); Naringenin (5,7,4′-Trihydroxyflavanone);3,5,7,3′,4′-Pentahydroxyflavanone; Flavanone; Pelargonidin chloride(3,5,7,4′-Tetrahydroxyflavylium chloride); Hinokitiol (b-Thujaplicin;2-hydroxy-4-isopropyl-2,4,6-cycloheptatrien-1-one); L-(+)-Ergothioneine((S)-a-Carboxy-2,3-dihydro-N,N,N-trimethyl-2-thioxo-1H-imidazole-4-ethanaminiuminner salt); Caffeic Acid Phenyl Ester; MCI-186(3-Methyl-1-phenyl-2-pyrazolin-5-one); HBED (N,N′-Di-(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic acid-H₂O); Ambroxol(trans-4-(2-Amino-3,5-dibromobenzylamino) cyclohexane-HCl; and U-83836E((−)-2-((4-(2,6-di-1-Pyrrolidinyl-4-pyrimidinyl)-1-piperazinyl)methyl)-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol.2HCl).Analogs and derivatives thereof can also be used.

The subject application provides compositions useful for inducing anincrease in fatty acid oxidation and mitochondrial biogenesis in asubject. Such compositions contain: HMB in combination with resveratrol;leucine in combination with resveratrol; both leucine and HMB incombination with resveratrol; KIC in combination with resveratrol; bothKIC and HMB in combination with resveratrol; both KIC and leucine incombination with resveratrol; or KIC, HMB and leucine in combinationwith resveratrol.

Branched Chain Amino Acids

Branched chain amino acids that can be combined with a PDE-5 inhibitorhave aliphatic side chains with a branch carbon atom that is bound totwo or more other atoms. The other atoms may be carbon atoms. Examplesof branched chain amino acids include leucine, isoleucine, and valine.Branched chain amino acids may also include other compounds, such as4-hydroxyisoleucine. In some embodiments, the compositions aresubstantially free of one or more, or all of non-branched chain aminoacids. In some embodiments, the compositions are substantially free ofone or more, or all of non-branched chain amino acids in free amino acidform. For example, the compositions can be substantially free ofalanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid,glutamine, glycine, histidine, lysine, methionine, phenylalanine,proline, serine, threonine, tryptophan, and/or tyrosine. Thecompositions can be substantially free of alanine, arginine, asparagine,aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine,lysine, methionine, phenylalanine, proline, serine, threonine,tryptophan, and/or tyrosine in free amino acid form. In someembodiments, the branched chain amino acid is leucine. In someembodiments, the compositions may be substantially free of isoleucineand/or valine, which may be in free form. The synergistic effectsbetween leucine and a PDE5 inhibitor, as described herein, are notobserved when leucine is substituted with isoleucine and valine. Notwishing to be bound by any particular theory, isoleucine, valine, andleucine compete with each other for transport and/or absorption, andinclusion of isoleucine and valine in a composition would reduce theefficacy of any leucine in the composition. Furthermore, isoleucine andvaline each lack substantial ability to activate the sirt signalingpathway, including Sirt1 and/or AMPK.

Branched chain amino acids may be present in the composition in freeamino acid form. The composition can be substantially free of alanine,arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine,glycine, histidine, isoleucine, lysine, methionine, phenylalanine,proline, serine, threonine, tryptophan, tyrosine, or valine in freeamino acid form. In some embodiments, the composition is substantiallyfree of non-branched chain amino acids that are not in free form (e.g.,non-branched chain amino acids that have formed peptide bonds with otheramino acids).”

Without being limited to theory, ingestion of branched chain aminoacids, such as leucine, can stimulate tissue protein synthesis via bothmTOR-dependent and -independent pathways, as well as to exert anantiproteolytic effect. These effects predominate in muscle, but alsocan manifest in other tissues, including adipose tissue. Given theenergetic cost of protein synthesis and turnover, leucine may increasefatty acid oxidation and net energy utilization and attenuate adiposity.Indeed, leucine has been reported to exert a thermogenic effect and toaugment weight and adipose tissue loss during energy restriction. Also,leucine and leucine-rich diets can favorably modulate inflammatorycytokine patterns in adipocytes and mice.

In some embodiments, any of the compositions described herein caninclude salts, derivatives, metabolites, catabolites, anabolites,precursors, and analogs of any of the branched chain amino acids. Themetabolites can be metabolites of leucine, such as HMB. The metabolitesof branched chain amino acids can include hydroxymethylbutyrate (HMB),α-hydroxyisocaproic acid, and keto-isocaproic acid (KIC), ketoisovalerate, and keto isocaproate. Non-limiting exemplary anabolites ofbranched chain amino acids can include glutamate, glutamine, threonine,α-ketobytyrate, α-aceto-α-hydroxy butyrate,α,β-dihydroxy-β-methylvalerate, α-keto-β-methylvalerate, α,β-dihydroxyisovalerate, and α-keto isovalerate.

In certain embodiments of the invention, any of the compositionsdisclosed herein can be formulated such that they do not contain (orexclude) one or more amino acids selected from the group consisting oflysine, glutamate, proline, arginine, valine, isoleucine, aspartic acid,asparagine, glycine, threonine, serine, phenylalanine, tyrosine,histidine, alanine, tryptophan, methionine, glutamine, taurine,carnitine, cystine and cysteine. In certain embodiments of theinvention, any of the compositions disclosed herein can be formulatedsuch that they do not contain (or exclude) one or more free amino acidsselected from the group consisting of lysine, glutamate, proline,arginine, valine, isoleucine, aspartic acid, asparagine, glycine,threonine, serine, phenylalanine, tyrosine, histidine, alanine,tryptophan, methionine, glutamine, taurine, carnitine, cystine andcysteine. In some cases, the compositions do not contain anynon-branched chain amino acids. In some cases, the compositions do notcontain any non-branched chain amino acids in free amino acid form. Themass or molar amount of a non-branched chain amino acid can be less than0.01, 0.1, 0.5, 1, 2, or 5% of the total composition. The mass or molaramount of a non-branched chain amino acid in free amino acid form can beless than 0.01, 0.1, 0.5, 1, 2, or 5% of the total composition. The massor molar amount of any branched-chain amino acid or metabolite thereof,aside from leucine or its metabolites can be less than 0.01, 0.1, 0.5,1, 2, or 5% of the total composition. The mass or molar amount of anybranched-chain amino acid in free amino acid form or metabolite thereof,aside from leucine or its metabolites can be less than 0.01, 0.1, 0.5,1, 2, or 5% of the total composition.

Vitamin B6

In some embodiments, a composition described herein can comprise a PDE 5inhibitor, leucine and/or a leucine metabolite, and vitamin B6. In otherembodiments, a composition can comprise sildenafil, resveratrol, andvitamin B6. The leucine may be in free amino acid form.

Without being limited to any particular theory or mode of action,elevations in the active B6 metabolite (pyridoxal phosphate) can reducethe tone and activity of the adipocyte calcium channel. Intracellularfree Ca2+ is a primary regulator of adipocyte fatty acid synthaseexpression and activity, which can result in a suppression of both theexpression and activity of fatty acid synthase, which in turn is one ofthe rate limiting steps in neutral lipid synthesis in adipocytes.

As used herein, vitamin B6 includes its different forms, includingpyridoxine, pyridoxine 5′-phosphate, pyridoxal, pyridoxal phosphate,pyridoxal 5′-phosphate, pyridoxamine, pyridoxamine 5′-phosphate. Inother embodiments, vitamin B6 can also include 4-pyridoxic acid, whichis a catabolite of the above forms of vitamin B6 that is excreted. Thecompositions described herein can include any one or more of these formsof vitamin B6.

The active form of vitamin B6 in the body is pyridoxal 5-phosphate,which is a coenzyme for all transamination and some decarboxylation anddeamination reactions. Furthermore, pyridoxal 5-phosphate is required asa coenzyme for all transamination reactions which occur in the body(Peterson D L, Martinez-Carrion M. The mechanism of transamination.Function of the histidyl residue at the active site of supernatantaspartate transaminase. J Biol Chem. 1970 Feb. 25; 245(4):806-13).

In some embodiments, any of the compositions described herein caninclude salts, derivatives, metabolites, catabolites, anabolites,precursors, and analogs of any of the forms of vitamin B6. Exemplarycatabolites of vitamin B6 include2-methyl-3-hydroxy-5-formylpyridine-4-carboxylate and3-hydroxy-2-methylpyridine-4,5-dicarboxylate. Exemplary analogs ofvitamin B6 are described in U.S. Pat. Nos. 7,230,009, and 6,369,042.Exemplary precursors of vitamin B6 are described in U.S. Pat. No.7,495,101.

Pharmaceutically Active Agents

The subject compositions can further include one or morepharmaceutically active agents other than a PDE-5 inhibitor. Examples oftherapeutically active agents include ibuprofen, aldoril, andgemfebrozil, verapamil, maxzide, diclofenac and metrolol, maproltiline,triazolam and minoxidil. For example, the combination compositions cancomprise a pharmaceutically active anti-diabetic agent, weight lossagent, or calcium regulation agent. U.S. Pat. No. 7,109,198 and U.S.Patent Application No. 20090142336, which are both incorporated byreference herein, describe a variety of pharmaceutically active agentsor therapeutically active agents suitable for inclusion in a combinationcomposition described herein. Examples of anti-diabetic agents includebiguanides (such as metformin), thiazoladinediones and meglitinides(such as repaglinide, pioglitazone, and rosiglitazone), alphaglucosidease inhibitors (such as acarbose), sulfonylureas (such astolbutamide, acetohexamide, tolazamide, chlorpropamide, glipizide,glyburide, glimepiride, gliclazide), incretins, ergot alkaloids (such asbromocriptine), and DPP inhibitors (such as sitagliptin, vildagliptin,saxagliptin, lingliptin, dutogliptin, gemigliptin, alogliptin, andberberine). The anti-diabetic agent can be an oral anti-diabetic agent.The anti-diabetic agent can also be injectable anti-diabetic drugs,including insulin, amylin analogues (such as pramlintide), and inretinmimetics (such as exenatide and liraglutide). Examples of anti-obesitytherapeutic agents include lipase inhibitors (such as Orlistat),dopaminergic, noradrenergic, and serotoninergic compounds, cannabinoidreceptor antagonists (such as rimonabant), exenatide, pramlintide, andCNS agents (such as topimerate). These examples are provided fordiscussion purposes only, and are intended to demonstrate the broadscope of applicability of the invention to a wide variety of drugs. Itis not meant to limit the scope of the invention in any way.

In some embodiments, a PDE-5 inhibitor can be combined with a pair ofpharmaceutically active agents as follow: glipizide and metformin;glyburide and metformin; pioglitazone and glimepiride; pioglitazone andmetformin; repaglinide and metformin; rosiglitazone and glimepiride;rosiglitazone and metformin; and sitagliptin and metformin.

The amount of pharmaceutical agent, or any other component used in acombination composition described herein, can be a used in an amountthat is therapeutically effective. The amount of pharmaceutical agent,or any other component used in a combination composition describedherein, can be a used in an amount that is sub-therapeutic. In someembodiments, using sub-therapeutic amounts of an agent or component canreduce the side-effects of the agent. Use of sub-therapeutic amounts canstill be effective, particularly when used in synergy with other agentsor components.

A sub-therapeutic amount of the agent or component can be such that itis an amount below which would be considered therapeutic. For example,FDA guidelines can suggest a specified level of dosing to treat aparticular condition, and a sub-therapeutic amount would be any levelthat is below the FDA suggested dosing level. The sub-therapeutic amountcan be about 1, 5, 10, 15, 20, 25, 30, 35, 50, 75, 90, or 95% less thanthe amount that is considered to be a therapeutic amount. Thetherapeutic amount can be assessed for individual subjects, or forgroups of subjects. The group of subjects can be all potential subjects,or subjects having a particular characteristic such as age, weight,race, gender, or physical activity level.

In the case of metformin hydrochloride, the physician suggested startingdose is 1000 mg daily, with subject specific dosing having a range of500 mg to a maximum of 2500 mg daily (metformin hydrochlorideextended-release tablets labelwww.accessdata.fda.gov/drugsatfda_docs/label/2008/021574s0101bl.pdf).The particular dosing for a subject can be determined by a clinician bytitrating the dose and measuring the therapeutic response. Thetherapeutic dosing level can be determined by measuring fasting plasmaglucose levels and measuring glycosylated hemoglobin. A sub-therapeuticamount can be any level that would be below the recommended dosing ofmetformin. For example, if a subject's therapeutic dosing level isdetermined to be 700 mg daily, a dose of 600 mg would be asub-therapeutic amount. Alternatively, a sub-therapeutic amount can bedetermined relative to a group of subjects rather than an individualsubject. For example, if the average therapeutic amount of metformin forsubjects with weights over 300 lbs is 2000 mg, then a sub-therapeuticamount can be any amount below 2000 mg. In some embodiments, the dosingcan be recommended by a healthcare provider including, but not limitedto a patient's physician, nurse, nutritionist, pharmacist, or otherhealth care professional. A health care professional may include aperson or entity that is associated with the health care system.Examples of health care professionals may include surgeons, dentists,audiologists, speech pathologists, physicians (including generalpractitioners and specialists), physician assistants, nurses, midwives,pharmaconomists/pharmacists, dietitians, therapists, psychologists,physical therapists, phlebotomists, occupational therapists,optometrists, chiropractors, clinical officers, emergency medicaltechnicians, paramedics, medical laboratory technicians, radiographers,medical prosthetic technicians social workers, and a wide variety ofother human resources trained to provide some type of health careservice.

Dosing Amounts

The invention provides for compositions that are combinations ofisolated components, such as leucine, metabolites of leucine, such asHMB, sildenafil, icariin, and resveratrol, that have been isolated fromone or more sources. The invention provides for compositions that areenriched in leucine, metabolites of leucine, such as HMB, sildenafil,icariin, and/or resveratrol. The components can be isolated from naturalsources or created from synthetic sources and then enriched to increasethe purity of the components. For example, sildenafil can be createdfrom a synthetic source and then enriched by one or more purificationmethods. Additionally, leucine (e.g., free leucine), can be isolatedfrom a natural source and then enriched by one or more separations. Theisolated and enriched components, such as sildenafil and leucine, canthen be combined and formulated for administration to a subject.

In some embodiments, a composition comprises an amount of a selectivePDE inhibitor (e.g., PDE-5 inhibitor including but not limited tosildenafil or icariin). The amount of a PDE inhibitor may be asubtherapeutic amount, and/or an amount that is synergistic with one ormore other compounds in the composition or one or more of the compoundsadministered simultaneously or in close temporal proximity with thecomposition. In some embodiments, the PDE inhibitor is administered in alow dose, a medium dose, or a high dose, which describes therelationship between two doses, and generally do not define anyparticular dose range.

A daily dose of sildenafil can be about or less than about 0.05, 0.1,0.5, 1, 2, 5, 10, 20, 40, 60, 80, or 100 mg of sildenafil. In otherembodiments, a daily dose of icariin can be about or less than about 1,10, 20, 50, 100, 150, 300, 400, 500, 750, 1000, 1500, or 2000 mg oficariin. A daily low dose of resveratrol may comprise about, less thanabout, or more than about 0.5 mg/kg, 1 mg/kg, 2.5 mg/kg, 5 mg/kg, 7.5mg/kg, 10 mg/kg, 12.5 mg/kg, 15 mg/kg, 20 mg/kg, 25 mg/kg, 50 mg/kg, 75mg/kg, 100 mg/kg, or more; a daily medium dose of resveratrol maycomprise about, less than about, or more than about 20 mg/kg, 25 mg/kg,50 mg/kg, 75 mg/kg, 100 mg/kg, 125 mg/kg, 150 mg/kg, 175 mg/kg, 200mg/kg, 250 mg/kg, or more; and a daily high dose of resveratrol maycomprise about, less than about, or more than about 150 mg/kg, 175mg/kg, 200 mg/kg, 225 mg/kg, 250 mg/kg, 300 mg/kg, 350 mg/kg, 400 mg/kg,or more.

Another aspect of the invention provides compositions comprisingsynergizing amounts of PDE-5 inhibitor, such as sildenafil and icariin,in combination with leucine, HMB, KIC, vitamin D, vitamin K2, and/orresveratrol. These synergizing amounts can be as follows: leucine about,less than about, or more than about 0.5-3.0 g/day (e.g. 0.5, 0.75, 1,1.25, 1.5, 1.75, 2, 2.5, 3, or more g/day); HMB about, less than about,or more than about 0.20-3.0 g/day (e.g. 0.2, 0.4, 0.5, 0.75, 1, 1.5, 2,2.5, 3, or more g/day); KIC about, less than about, or more than about0.2-3.0 g/day (e.g. 0.2, 0.4, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3,or more g/day); vitamin D about, less than about, or more than about2.5-25 μg/day (e.g. 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 25, or moreμg/day); vitamin K2 about, less than about, or more than about 5-200μg/day (e.g. 5, 10, 25, 50, 75, 100, 150, 200, or more μg/day);sildenafil about, less than about, or more than about 0.05-100 mg/day(e.g., 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, 40, 60, 80, or 100 mg/day);icariin about, less than about, or more than about 1-2000 mg (e.g., 1,10, 20, 50, 100, 150, 300, 400, 500, 750, 1000, 1500, or 2000 mg/day)and/or resveratrol about, less than about, or more than about 10-500mg/day (e.g. 10, 25, 50, 51, 75, 100, 150, 200, 250, 300, 350, 400, 450,500, or more mg/day). Thus, one embodiment provides a compositioncomprising leucine in an amount of about 0.75 to about 3.0 g (0.75 to3.0 g) and sildenafil in an amount between about 0.05 and about 100 mg(or 0.05 to 100 mg). Another embodiment provides a compositioncomprising HMB in an amount of 0.40-3.0 g (or 0.40 to 3.0 g) andsildenafil in an amount between 0.05-100 mg (or 0.050 to 100 mg).Another embodiment provides for a composition comprising leucine in anamount of about 0.75-about 3.0 g (or 0.75 to 3.0 g), HMB in an amount ofabout 0.40 and about 3.0 g (or 0.40 to 3.0 g) and sildenafil in anamount between about 0.05 and about 100 mg (or 0.05 to 100 mg). Incompositions comprising a PDE inhibitor or methods comprisingadministration of a PDE inhibitor (separately from or concurrently withone or more other components), the PDE inhibitor may be provided in anamount that produces a peak plasma concentration of about, less thanabout, or more than about 0.1, 1, 5, 10, 25, 50, 100, 500, 1000, 2500,5000, 10000, or more nM.

Another embodiment provides for a composition containing synergizingamounts of sildenafil and resveratrol, in combination with HMB orleucine. In such compositions, the total amount of leucine and HMBwithin the composition can be less than 3.0 g (or less than about 3.0 g;e.g. less than about 0.7, 0.75, 1, 1.5, 2, 2.5, 3 grams) and at least0.70 g (or at least about 0.70 g; e.g. at least about 0.7, 0.75, 1, 1.5,2, 2.5, 3 grams). Compositions containing both leucine and HMB cancontain amounts of leucine and HMB that total about, less than about, ormore than about 0.70 g to 3.0 g (about 0.70 g to about 3.0 g; e.g. 0.7,1, 1.25, 1.5, 1.75, 2, 2.5, 3, or more grams), 0.75 g to 3.0 g (about0.75 g to about 3.0 g), or 1.0 g to 3.0 g (about 1.0 g to about 3.0 g)within the composition and resveratrol in synergizing amounts (at least35 mg of resveratrol and no more than 500 (or about 500) mg resveratrol(e.g. about, less than about, or more than about 35, 50, 75, 100, 150,200, 250, 300, 350, 400, 450, or 500 mg resveratrol) or an amount ofresveratrol between 50 and 500 mg (or about 50 to about 500 mg).

In some embodiments a unit dosage can comprise a PDE 5 inhibitor, suchas sildenafil, in combination with one or more other components. In someembodiments, a unit dosage comprises one or more of: about, less thanabout, or more than about can be about or less than about 0.05, 0.1,0.5, 1, 2, 5, 10, 20, 40, 60, 80, or 100 mg of a selective PDE-5inhibitor (e.g., sildenafil); about, less than about, or more than about50, 100, 200, 300, 400, 500 or more mg of HMB; about, less than about,or more than about 10, 20, 30, 40, 50, 75, 100, or more mg resveratrol;about, less than about, or more than about 2.5, 5, 7.5, 10, 12.5, 15,17.5, 20, or more mg of vitamin B6; about, less than about, or more thanabout 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 25, or more μg of vitamin D;about, less than about, or more than about 5, 10, 25, 50, 75, 100, 150,200, or more μg of vitamin K2; and about, less than about, or more thanabout 400, 500, 600, 700, 800, 900, 1000, 1100, 1250, 1500, or more mgof leucine. A unit dosage can comprise about, less than about, or morethan about 500 mg beta hydroxyl, beta methyl butyrate and about, lessthan about, or more than about 50 mg resveratrol. A unit dosage cancomprise about, less than about, or more than about 500 mg beta hydroxy,beta methyl butyrate; and about, less than about, or more than about 50mg resveratrol; and about, less than about, or more than about 15 mgvitamin B6.

In some embodiments, a unit dosage can comprise between about 0.1-10 mgof sildenafil. In some embodiments, a unit dosage can comprise betweenabout 0.5-100 mg of avanafil, 0.05-20 mg of iodenafil, 0.25-50 mg ofmirodenafil, 0.01-2.5 mg of tadalafil, 0.01-2.5 mg of vardenafil,0.5-100 mg of udenafil, or 0.5-100 mg of zaprinst. In some embodiments,a unit dosage can comprise between about 0.5-50 mg of avanafil, 0.05-10mg of iodenafil, 0.25-25 mg of mirodenafil, 0.01-1.25 mg of tadalafil,0.01-1.25 mg of vardenafil, 0.5-50 mg of udenafil, or 0.5-50 mg ofzaprinst.

In some embodiments, a unit dosage can comprise chlorogenic acid (e.g.about, less than about, or more than about 25, 50, 75, 100, 150, 200, ormg) in combination with one or more other components in about, less thanabout, or more than about the indicated amounts. A unit dosage cancomprise 500 mg beta hydroxy, beta methyl butyrate (e.g. 50, 100, 200,300, 400, 500 or more mg) and 100 mg chlorogenic acid. A unit dosage cancomprise 500 mg beta hydroxy, beta methyl butyrate (e.g. 50, 100, 200,300, 400, 500 or more mg); and 100 mg chlorogenic acid; and 15 mgvitamin B6. A unit dosage can comprise 1.125 g leucine (e.g. 400, 500,600, 700, 800, 900, 1000, 1100, 1250, or more mg) and 100 mg chlorogenicacid. A unit dosage can comprise 1.125 g leucine (e.g. 400, 500, 600,700, 800, 900, 1000, 1100, 1250, or more mg); 100 mg chlorogenic acid;and 15 mg vitamin B6 (e.g. 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, or moremg). A unit dosage can comprise 750 mg leucine, 75 mg chlorogenic acidand 10 mg vitamin B6.

In some embodiments a unit dosage can comprise quinic acid in about,less than about, or more than about the indicated amounts (e.g. 10, 15,20, 25, 30, 40, 50, or more mg), in combination with one or more othercomponents in about, less than about, or more than about the indicatedamounts. A unit dosage can comprise 500 mg beta hydroxy, beta methylbutyrate (e.g. 50, 100, 200, 300, 400, 500 or more mg) and 25 mg quinicacid. A unit dosage can comprise 500 mg beta hydroxy, beta methylbutyrate (e.g. 50, 100, 200, 300, 400, 500 or more mg), 25 mg quinicacid and 15 mg vitamin B6 (e.g. 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, ormore mg). A unit dosage can comprise 1.125 g leucine (e.g. 400, 500,600, 700, 800, 900, 1000, 1100, 1250, or more mg) and 25 mg quinic acid.A unit dosage can comprise 1.125 g leucine (e.g. 400, 500, 600, 700,800, 900, 1000, 1100, 1250, or more mg), 25 mg quinic acid and 15 mgvitamin B6 (e.g. 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, or more mg). Aunit dosage can comprise 750 mg leucine, 15 mg quinic acid and 10 mgvitamin B6.

In some embodiments a unit dosage can comprise fucoxanthin in about,less than about, or more than about the indicated amounts (e.g. 0.5,0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 3, 5, or more mg) in combinationwith one or more other components in about, less than about, or morethan about the indicated amounts. A unit dosage can comprise 500 mg betahydroxy, beta methyl butyrate (e.g. 50, 100, 200, 300, 400, 500 or moremg) and 2.5 mg fucoxanthin. A unit dosage can comprise 500 mg betahydroxy, beta methyl butyrate (e.g. 50, 100, 200, 300, 400, 500 or moremg), 2.5 mg fucoxanthin and 15 mg vitamin B6 (e.g. 2.5, 5, 7.5, 10,12.5, 15, 17.5, 20, or more mg). A unit dosage can comprise 1.125 gleucine (e.g. 400, 500, 600, 700, 800, 900, 1000, 1100, 1250, or moremg) and 2.5 mg fucoxanthin. A unit dosage can comprise 1.125 g leucine(e.g. 400, 500, 600, 700, 800, 900, 1000, 1100, 1250, or more mg), 2.5mg fucoxanthin and 15 mg vitamin B6 (e.g. 2.5, 5, 7.5, 10, 12.5, 15,17.5, 20, or more mg). A unit dosage can comprise 750 mg leucine, 1.5 mgfucoxanthin and 10 mg vitamin B6.

In some embodiments, a composition comprises an amount of anantidiabetic agent, such as a biguanide (e.g. metformin). The amount ofantidiabetic agent may be a subtherapeutic amount, and/or an amount thatis synergistic with one or more other compounds in the composition orone or more of the compounds administered simultaneously or in closetemporal proximity with the composition. In some embodiments, theantidiabetic agent is administered in a very low dose, a low dose, amedium dose, or a high dose, which describes the relationship betweentwo doses, and generally do not define any particular dose range. Forexample, a daily very low dose of metformin may comprise about, lessthan about, or more than about 5 mg/kg, 10 mg/kg, 25 mg/kg, 50 mg/kg, 75mg/kg, 100 mg/kg, or more; a daily low dose of metformin may compriseabout, less than about, or more than about 75 mg/kg, 100 mg/kg, 150mg/kg, 175 mg/kg, 200 mg/kg, or more; a daily medium dose of metforminmay comprise about, less than about, or more than about 150 mg/kg, 175mg/kg, 200 mg/kg, 250 mg/kg, 300; and a daily high dose of metformin maycomprise about, less than about, or more than about 200 mg/kg, 250mg/kg, 300 mg/kg, 350 mg/kg, 400 mg/kg, 500 mg/kg, 700 mg/kg, or more.

In some embodiments a unit dosage can comprise metformin in about, lessthan about, or more than about the indicated amounts (e.g. 25, 50, 100,150, 200, 250, 300, 400, 500, or more mg) in combination with one ormore other components in about, less than about, or more than about theindicated amounts (such as 10, 20, 30, 40, 50, 75, 100, or more mg ofresveratrol; 50, 100, 200, 300, 400, 500 or more mg HMB; and/or 400,500, 600, 700, 800, 900, 1000, 1100, 1250, or more mg of leucine). Aunit dosage can comprise about, less than about or more than about 50 mgmetformin, 500 mg beta hydroxy, beta methyl butyrate and 50 mgresveratrol. A unit dosage can comprise about, less than about or morethan about 50 mg metformin, 1.125 g leucine and 50 mg resveratrol. Aunit dosage can comprise about, less than about or more than about 100mg metformin, 500 mg beta hydroxy, beta methyl butyrate and 50 mgresveratrol. A unit dosage can comprise about, less than about or morethan about 100 mg metformin, 1.125 g leucine and 50 mg resveratrol. Aunit dosage can comprise about, less than about or more than about 250mg metformin, 500 mg beta hydroxy, beta methyl butyrate and 50 mgresveratrol. A unit dosage can comprise about, less than about or morethan about 250 mg metformin, 1.125 g leucine and 50 mg resveratrol. Insome embodiments, a composition further comprises a PDE inhibitor in asynergizing amount. In some embodiments, a metformin composition furthercomprises a selective PDE inhibitor in a synergizing amount.

In some embodiments, a unit dosage comprises leucine and icariin. Theunit dosage can comprise about 500 to about 2000 mg of leucine. The unitdosage can comprise about 700 to about 1500 mg of leucine. The unitdosage can comprise about 900 to about 1300 mg of leucine. The weightratio of icariin relative to leucine can be 0.01-0.1. The weight ratioof icariin relative to leucine can be 0.02-0.06. The weight ratio oficariin relative to leucine can be 0.03-0.05. An exemplary formulationof a unit dosage comprising leucine and icariin is shown in Table 1.

TABLE 1 Formulation 1 Wt ratio (relative Mass to Component (mg) Leucine)Leucine 1110 1 Icariin 50 0.045

In some embodiments, a unit dosage comprises leucine, icariin, andresveratrol. The unit dosage can comprise about 500 to about 2000 mg ofleucine. The unit dosage can comprise about 700 to about 1500 mg ofleucine. The unit dosage can comprise about 900 to about 1300 mg ofleucine. The weight ratio of icariin relative to leucine can be0.01-0.1. The weight ratio of icariin relative to leucine can be0.02-0.06. The weight ratio of icariin relative to leucine can be0.03-0.05. The weight ratio of resveratrol relative to leucine can be0.01-0.1. The weight ratio of resveratrol relative to leucine can be0.02-0.06. The weight ratio of resveratrol relative to leucine can be0.03-0.05. An exemplary formulation of a unit dosage comprising leucine,icariin, and resveratrol is shown in Table 2.

TABLE 2 Formulation 2 Wt ratio (relative Mass to Component (mg) Leucine)Leucine 1110 1 Icariin 50 0.045 Resveratrol 50 0.045

In some embodiments, a unit dosage comprises leucine, icariin, andmetformin. The unit dosage can comprise about 500 to about 2000 mg ofleucine. The unit dosage can comprise about 700 to about 1500 mg ofleucine. The unit dosage can comprise about 900 to about 1300 mg ofleucine. The weight ratio of icariin relative to leucine can be0.01-0.1. The weight ratio of icariin relative to leucine can be0.02-0.06. The weight ratio of icariin relative to leucine can be0.03-0.05. The weight ratio of metformin relative to leucine can be0.01-0.6. The weight ratio of metformin relative to leucine can be0.1-0.5. The weight ratio of metformin relative to leucine can be0.15-0.3. The weight ratio of metformin relative to leucine can be0.22-0.23. An exemplary formulation of a unit dosage comprising leucine,icariin, and metformin is shown in Table 3.

TABLE 3 Formulation 3 Wt ratio (relative Mass to Component (mg) Leucine)Leucine 1110 1 Icariin 50 .045 metformin 250 .225

In some embodiments, a unit dosage comprises leucine and sildenafil. Theunit dosage can comprise about 500 to about 2000 mg of leucine. The unitdosage can comprise about 700 to about 1500 mg of leucine. The unitdosage can comprise about 900 to about 1300 mg of leucine. The weightratio of sildenafil relative to leucine can be 0.00001-0.05. The weightratio of sildenafil relative to leucine can be 0.0001-0.03. The weightratio of sildenafil relative to leucine can be 0.001-0.02. The weightratio of sildenafil relative to leucine can be 0.005-0.015. An exemplaryformulation of a unit dosage comprising leucine and sildenafil is shownin Table 4.

TABLE 4 Formulation 4 Wt ratio (relative Mass to Component (mg) Leucine)Leucine 1110 1 Sildenafil 10 0.009

In some embodiments, a unit dosage comprises leucine, resveratrol, andsildenafil. The unit dosage can comprise about 500 to about 2000 mg ofleucine. The unit dosage can comprise about 700 to about 1500 mg ofleucine. The unit dosage can comprise 900-1300 mg of leucine. The weightratio of resveratrol relative to leucine can be 0.00001-0.05. The weightratio of resveratrol relative to leucine can be 0.0001-0.03. The weightratio of resveratrol relative to leucine can be 0.001-0.02. The weightratio of sildenafil relative to leucine can be 0.00001-0.05. The weightratio of sildenafil relative to leucine can be 0.0001-0.03. The weightratio of sildenafil relative to leucine can be 0.001-0.02. The weightratio of sildenafil relative to leucine can be 0.005-0.015. An exemplaryformulation of a unit dosage comprising leucine, resveratrol, andsildenafil is shown in Table 5.

TABLE 5 Formulation 5 Wt ratio (relative Mass to Component (mg) Leucine)Leucine 1110 1 Resveratrol 10 0.009 Sildenafil 10 0.009

In some embodiments, a unit dosage comprises HMB and icariin. The unitdosage can comprise about 50-1000 mg of HMB. The unit dosage cancomprise about 100-500 mg of HMB. The unit dosage can comprise 150-400mg of HMB. The unit dosage can comprise 200-300 mg of HMB. The weightratio of icariin relative to HMB can be 0.05-0.5. The weight ratio oficariin relative to HMB can be 0.07-0.4. The weight ratio of icariinrelative to HMB can be 0.1-0.3. An exemplary formulation of a unitdosage comprising HMB and icariin is shown in Table 6.

TABLE 6 Formulation 6 Wt ratio (relative Mass to Component (mg) HMB) HMB250 1 Icariin 50 0.2

In some embodiments, a unit dosage comprises HMB, icariin, andresveratrol. The unit dosage can comprise about 50-1000 mg of HMB. Theunit dosage can comprise about 100-500 mg of HMB. The unit dosage cancomprise about 150-400 mg of HMB. The unit dosage can comprise 200-300mg of HMB. The weight ratio of icariin relative to HMB can be 0.05-0.5.The weight ratio of icariin relative to HMB can be 0.07-0.4. The weightratio of icariin relative to HMB can be 0.1-0.3. The weight ratio ofresveratrol relative to HMB can be 0.05-0.5. The weight ratio ofresveratrol relative to HMB can be 0.07-0.4. The weight ratio ofresveratrol relative to HMB can be 0.1-0.3. An exemplary formulation ofa unit dosage comprising HMB, icariin, and resveratrol is shown in Table7.

TABLE 7 Formulation 7 Wt ratio (relative Mass to Component (mg) HMB) HMB250 1 Icariin 50 0.2 Resveratrol 50 0.2

In some embodiments, a unit dosage comprises HMB, icariin, andmetformin. The unit dosage can comprise about 50 to about 1000 mg ofHMB. The unit dosage can comprise about 100 to about 500 mg of HMB. Theunit dosage can comprise about 150 to about 400 mg of HMB. The unitdosage can comprise about 200 to about 300 mg of HMB. The weight ratioof icariin relative to HMB can be 0.05-0.5. The weight ratio of icariinrelative to HMB can be 0.07-0.4. The weight ratio of icariin relative toHMB can be 0.1-0.3. The weight ratio of metformin relative to HMB can be0.2-4. The weight ratio of metformin relative to HMB can be 0.5-2. Theweight ratio of metformin relative to HMB can be 0.75-1.25. An exemplaryformulation of a unit dosage comprising HMB, icariin, and metformin isshown in Table 8.

TABLE 8 Formulation 8 Wt ratio (relative Mass to Component (mg) HMB) HMB250 1 Icariin 50 0.2 Metformin 250 1

In some embodiments, a unit dosage comprises HMB and sildenafil. Theunit dosage can comprise about 50-1000 mg of HMB. The unit dosage cancomprise about 100-500 mg of HMB. The unit dosage can comprise about150-400 mg of HMB. The unit dosage can comprise 200-300 mg of HMB. Theweight ratio of sildenafil relative to HMB can be 0.01-0.1. The weightratio of sildenafil relative to HMB can be 0.02-0.08. The weight ratioof sildenafil relative to HMB can be 0.03-0.05. An exemplary formulationof a unit dosage comprising HMB and sildenafil is shown in Table 9.

TABLE 9 Formulation 9 Wt ratio (relative Mass to Component (mg) HMB) HMB250 1 Sildenafil 10 0.04

In some embodiments, a unit dosage comprises HMB, sildenafil, andresveratrol. The unit dosage can comprise about 50-1000 mg of HMB. Theunit dosage can comprise about 100-500 mg of HMB. The unit dosage cancomprise about 150-400 mg of HMB. The unit dosage can comprise 200-300mg of HMB. The weight ratio of sildenafil relative to HMB can be0.01-0.1. The weight ratio of sildenafil relative to HMB can be0.02-0.08. The weight ratio of sildenafil relative to HMB can be0.03-0.05. The weight ratio of resveratrol relative to HMB can be0.01-0.1. The weight ratio of resveratrol relative to HMB can be0.02-0.08. The weight ratio of resveratrol relative to HMB can be0.03-0.05. An exemplary formulation of a unit dosage comprising HMB andsildenafil is shown in Table 10.

TABLE 10 Formulation 10 Wt ratio (relative Mass to Component (mg) HMB)HMB 250 1 Sildenafil 10 0.04 Resveratrol 10 0.04

In some embodiments, any of the unit dosages herein, e.g., described inTables 1-10 further comprise Vitamin B6. In some embodiments, any of theunit dosages herein, e.g., described in Tables 1-10 further comprise 15mg of Vitamin B6. The unit dosages can further comprise about 5-50 mg ofVitamin B6. The weight ratio of Vitamin B6 to HMB, if present, can beabout 0.06, 0.002-0.18, 0.03-0.12, or 0.05-0.07. The weight ratio ofVitamin B6 to Leucine, if present, can be about 0.0135, 0.005-0.03,0.007-0.025, or 0.01-0.017.

In some embodiments, the compositions described herein can besubstantially free of one or more specified components or have specifiedlevels of such components. The compositions, for example thecompositions described in Tables 1-10, can be substantially free, orcomprise less than 40, 20, 10, 15, 5, or 1% by total weight, of glycemiccarbohydrates. The compositions can be substantially free, or compriseless than 40, 20, 10, 15, 5, or 1% by total weight, of sugars,including, without limitation, glucose, dextrose, fructose and sucrose.The compositions can be substantially free, or comprise less than 40,20, 10, 15, 5, or 1% by total weight, of high glycemic indexcarbohydrates. The compositions can be substantially free, or compriseless than 40, 20, 10, 15, 5, or 1% by total weight, of complexcarbohydrates. The compositions can be substantially free, or compriseless than 40, 20, 10, 15, 5, or 1% by total weight, of simplecarbohydrates. The compositions can be substantially free, or compriseless than 40, 20, 10, 15, 5, or 1% by total weight, of starch, cornsyrup, short grain white rice, white flour.

In some embodiments of the invention, the combination compositions canhave a specified ratio of branched chain amino acids and/or metabolitesthereof to a selective PDE inhibitor. The specified ratio can providefor effective and/or synergistic regulation of energy metabolism. Forexample, the specified ratio can cause a decrease in weight gain of asubject, a decrease in visceral adipose volume of a subject, an increasein fat oxidation of a subject, an increase in insulin sensitivity of asubject, an increase of glucose uptake in muscle of a subject, adecrease in inflammation markers, an increase in vasodilatation, and/oran increase in body temperature. Such beneficial effects can resultfrom, in part, an increase in mitochondrial biogenesis, or a variety ofother changes in the energy metabolism pathway. The ratio of branchedchain amino acids and/or metabolites thereof to a selective PDEinhibitor activator can be a mass ratio, a molar ratio, or a volumeratio.

In some embodiments, the molar ratio of (a) branched chain amino acidsand/or metabolites thereof to (b) a selective PDE inhibitor about orgreater than about 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,85, 90, 100, 120, or 150. In other embodiments, the molar ratio of oneor more branched chain amino acids and/or metabolites thereof to aselective PDE inhibitor contained in the subject compositions is aboutor greater than about 20, 30, 40, 50, 60, 70, 80, 90, 95, 90, 95, 100,105, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 220, 250, 300,350, 400, or 500. In some embodiments, the molar ratio of component (a)to (b) in said composition is greater than about 20, 40, 60, 80, 100,120, or 150. In some embodiments, the molar ratio of component (a) to(b) in said composition is greater than about 80, 100, 120, or 150. Insome embodiments, the molar ratio of component (a) to (b) in saidcomposition is greater than about 80, 100, 120, or 150. In someembodiments, the molar ratio of component (a) to (b) in said compositionis greater than about 200, 250, or 300. In some embodiments, the molarratio of component (a) to (b) in said composition is greater than about40, 150, 250, or 500.

In some embodiments, the dosing of leucine, any metabolites of leucine,the PDE inhibitor (such as a PDE 5 inhibitor like sildenafil) can bedesigned to achieve a specified physiological concentration orcirculating level of leucine, metabolites of leucine and/or a PDE 5inhibitor. The physiological concentration can be a circulating level asmeasured in the blood stream of a subject. The subject can be a human oran animal. A selected dosing can be altered based on the characteristicsof the subject, such as weight, rate of energy metabolism, genetics,ethnicity, height, or any other characteristic. The amount of leucine ina unit dose can be such that the circulating level of leucine in asubject is about or greater than about 0.25 mM, 0.5 mM, 0.75 mM, or 1mM. A dosing of about 1,125 mg leucine (e.g., free leucine), can achievea circulating level of leucine in a subject that is about 0.5 mM. Adosing of about 300 mg leucine (e.g., free leucine), can achieve acirculating level of leucine in a subject that is about 0.25 mM. Thedosing of about sildenafil can achieve a circulating concentration ofabout or less than about 0.1, 0.5, 1, 2, 5, or 10 nM. In someembodiments, the target or achieved circulating concentration ofsildenafil is less than about 1 nM. A unit dose of about 20 mg ofsildenafil can achieve a circulating concentration of about 100 nM ofsildenafil. A unit dose of about 0.2 mg of sildenafil can achieve acirculating concentration of about 1 nM of sildenafil. The dosing ofabout icariin can achieve a circulating concentration of about or lessthan about 0.1, 0.5, 1, 2, 5, or 10 nM. In some embodiments, the targetor achieved circulating concentration of icariin is less than about 1nM. A unit dose of about 20 mg of icariin can achieve a circulatingconcentration of about 100 nM of icariin. A unit dose of about 0.1 mg oficariin can achieve a circulating concentration of about 1 nM oficariin.

In some embodiments, the molar or mass ratios are circulating molar ormass ratios achieved after administration one or more compositions to asubject. The compositions can be a combination composition describedherein. The molar ratio of a combination composition in a dosing formcan be adjusted to achieve a desired circulating molar ratio. The molarratio can be adjusted to account for the bioavailability, the uptake,and the metabolic processing of the one or more components of acombination composition. For example, if the bioavailability of acomponent is low, then the molar amount of a that component can beincreased relative to other components in the combination composition.In some embodiments, the circulating molar or mass ratio is achievedwithin about 0.1, 0.5, 0.75, 1, 3, 5, or 10, 12, 24, or 48 hours afteradministration. The circulating molar or mass ratio can be maintainedfor a time period of about or greater than about 0.1, 1, 2, 5, 10, 12,18, 24, 36, 48, 72, or 96 hours.

In some embodiments, the circulating molar ratio of leucine tosildenafil is about or greater than about 100,000, 250,000, 500,000,750,000 or more. In some embodiments, the circulating molar ratio of HMBto sildenafil is about or greater than about 1,000, 2,500, 5,000, 7,500or more. In some embodiments, the circulating molar ratio of resveratrolto sildenafil is about or greater than about 50, 100, 200, 400, 800 ormore.

The compositions can be administered to a subject such that the subjectis administered a selected total daily dose of the composition. Thetotal daily dose can be determined by the sum of doses administered overa 24 hour period. The total daily dose of the composition can includeabout 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, 40, 60, 80, or 100 mg ofsildenafil. The total daily dose of the composition can include about 1,10, 20, 50, 100, 150, 300, 400, 500, 750, 1000, 1500, or 2000 mg oficariin. The total daily dose of the composition can include at leastabout 250, 500, 750, 1000, 1125, 2000, 2250 mg or more of a branchedchain amino acid or metabolite thereof. The branched chain amino acidcan be leucine, HMB, or any other branched chain amino acid describedherein. The total daily dose of the composition can include at leastabout 3, 7.5, 15, 30, 45, 90 mg or more of B6. The total daily dose ofthe composition can have a mass ratio of branched chain amino acids ormetabolite thereof to vitamin B6 that is about, greater than about, orless than about 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 110, 120,130, 140, 150, 175, 200, 250, 500, 750, 1000, or more.

In some embodiments, a selected dose of a composition can beadministered to a subject such that the subject achieves a desiredcirculating level of the composition. The desired circulating level ofthe composition can be at least about 0.25, 0.5, 0.75, 1 mM or more ofleucine. The desired circulating level of the composition can be atleast about 10, 25, 50, 100, 150, or 200 nM or more of B6. The desiredcirculating level of the composition can be about 0.1, 0.5, 1, 2, 5, 10nM or more of sildenafil. The desired circulating level of thecomposition can be about 0.1, 0.5, 1, 2, 5, 10 nM or more of icariin.The selected dose can be chosen based on the characteristics of thesubject, such as weight, height, ethnicity, or genetics.

Dosing Forms

The compositions described herein can be compounded into a variety ofdifferent dosage forms. It can be used orally as a tablet, chewabletablet, caplets, capsule, soft gelatin capsules, lozenges or solution.It can also be used as a nasal spray or for injection when in itssolution form. In some embodiments, the composition may be a liquidcomposition suitable for oral consumption. Compositions of the inventionsuitable for oral administration can be presented as discrete dosageforms, such as capsules, cachets, or tablets, or liquids or aerosolsprays each containing a predetermined amount of an active ingredient asa powder or in granules, a solution, or a suspension in an aqueous ornon-aqueous liquid, an oil-in-water emulsion, or a water-in-oil liquidemulsion, including liquid dosage forms (e.g., a suspension or slurry),and oral solid dosage forms (e.g., a tablet or bulk powder). Oral dosageforms may be formulated as tablets, pills, dragees, capsules, emulsions,lipophilic and hydrophilic suspensions, liquids, gels, syrups, slurries,suspensions and the like, for oral ingestion by an individual or apatient to be treated. Such dosage forms can be prepared by any of themethods of formulation. For example, the active ingredients can bebrought into association with a carrier, which constitutes one or morenecessary ingredients. Capsules suitable for oral administration includepush-fit capsules made of gelatin, as well as soft, sealed capsules madeof gelatin and a plasticizer, such as glycerol or sorbitol. The push-fitcapsules can contain the active ingredients in admixture with fillersuch as lactose, binders such as starches, and/or lubricants such astalc or magnesium stearate and, optionally, stabilizers. Optionally, theinventive composition for oral use can be obtained by mixing acomposition a solid excipient, optionally grinding a resulting mixture,and processing the mixture of granules, after adding suitableauxiliaries, if desired, to obtain tablets or dragee cores. Suitableexcipients are, in particular, fillers such as sugars, includinglactose, sucrose, mannitol, or sorbitol; cellulose preparations such as,for example, maize starch, wheat starch, rice starch, potato starch,gelatin, gum tragacanth, methyl cellulose,hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/orpolyvinylpyrrolidone (PVP). In general, the compositions are prepared byuniformly and intimately admixing the active ingredient with liquidcarriers or finely divided solid carriers or both, and then, ifnecessary, shaping the product into the desired presentation. Forexample, a tablet can be prepared by compression or molding, optionallywith one or more accessory ingredients. Compressed tablets can beprepared by compressing in a suitable machine the active ingredient in afree-flowing form such as powder or granules, optionally mixed with anexcipient such as, but not limited to, a binder, a lubricant, an inertdiluent, and/or a surface active or dispersing agent. Molded tablets canbe made by molding in a suitable machine a mixture of the powderedcompound moistened with an inert liquid diluent.

The liquid forms, in which the formulations disclosed herein may beincorporated for administration orally or by injection, include aqueoussolution, suitably flavored syrups, aqueous or oil suspensions, andflavored emulsions with edible oils such as cottonseed oil, sesame oil,coconut oil, or peanut oil as well as elixirs and similar pharmaceuticalvehicles. Suitable dispersing or suspending agents for aqueoussuspensions include synthetic natural gums, such as tragacanth, acacia,alginate, dextran, sodium carboxymethyl cellulose, methylcellulose,polyvinylpyrrolidone or gelatin.

A subject can be treated by combination of an injectable composition andan orally ingested composition.

Liquid preparations for oral administration may take the form of, forexample, solutions, syrups or suspensions, or they may be presented as adry product for reconstitution with water or other suitable vehiclesbefore use. Such liquid preparations may be prepared by conventionalmeans with pharmaceutically acceptable additives such as suspendingagents (e.g., sorbitol syrup, methyl cellulose or hydrogenated ediblefats); emulsifying agents (e.g., lecithin or acacia); non-aqueousvehicles (e.g., almond oil, oily esters or ethyl alcohol); preservatives(e.g., methyl or propyl p-hydroxybenzoates or sorbic acid); andartificial or natural colors and/or sweeteners.

The preparation of pharmaceutical compositions of this invention isconducted in accordance with generally accepted procedures for thepreparation of pharmaceutical preparations. See, for example,Remington's Pharmaceutical Sciences 18th Edition (1990), E. W. Martined., Mack Publishing Co., PA. Depending on the intended use and mode ofadministration, it may be desirable to process the magnesium-counter ioncompound further in the preparation of pharmaceutical compositions.Appropriate processing may include mixing with appropriate non-toxic andnon-interfering components, sterilizing, dividing into dose units, andenclosing in a delivery device.

This invention further encompasses anhydrous compositions and dosageforms comprising an active ingredient, since water can facilitate thedegradation of some compounds. For example, water may be added (e.g.,5%) in the arts as a means of simulating long-term storage in order todetermine characteristics such as shelf-life or the stability offormulations over time. Anhydrous compositions and dosage forms of theinvention can be prepared using anhydrous or low moisture containingingredients and low moisture or low humidity conditions. Compositionsand dosage forms of the invention which contain lactose can be madeanhydrous if substantial contact with moisture and/or humidity duringmanufacturing, packaging, and/or storage is expected. An anhydrouscomposition may be prepared and stored such that its anhydrous nature ismaintained. Accordingly, anhydrous compositions may be packaged usingmaterials known to prevent exposure to water such that they can beincluded in suitable formulary kits. Examples of suitable packaginginclude, but are not limited to, hermetically sealed foils, plastic orthe like, unit dose containers, blister packs, and strip packs.

An ingredient described herein can be combined in an intimate admixturewith a pharmaceutical carrier according to conventional pharmaceuticalcompounding techniques. The carrier can take a wide variety of formsdepending on the form of preparation desired for administration. Inpreparing the compositions for an oral dosage form, any of the usualpharmaceutical media can be employed as carriers, such as, for example,water, glycols, oils, alcohols, flavoring agents, preservatives,coloring agents, and the like in the case of oral liquid preparations(such as suspensions, solutions, and elixirs) or aerosols; or carrierssuch as starches, sugars, micro-crystalline cellulose, diluents,granulating agents, lubricants, binders, and disintegrating agents canbe used in the case of oral solid preparations, in some embodimentswithout employing the use of lactose. For example, suitable carriersinclude powders, capsules, and tablets, with the solid oralpreparations. If desired, tablets can be coated by standard aqueous ornonaqueous techniques.

Some examples of materials which may serve as pharmaceuticallyacceptable carriers include: (1) sugars, such as lactose, glucose andsucrose; (2) starches, such as corn starch and potato starch; (3)cellulose, and its derivatives, such as sodium carboxymethyl cellulose,ethyl cellulose and cellulose acetate; (4) powdered tragacanth; (5)malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter andsuppository waxes; (9) oils, such as peanut oil, cottonseed oil,safflower oil, sesame oil, olive oil, corn oil and soybean oil; (10)glycols, such as propylene glycol; (11) polyols, such as glycerin,sorbitol, mannitol and polyethylene glycol; (12) esters, such as ethyloleate and ethyl laurate; (13) agar; (14) buffering agents, such asmagnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16)pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19)ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxiccompatible substances employed in pharmaceutical formulations.

Binders suitable for use in dosage forms include, but are not limitedto, corn starch, potato starch, or other starches, gelatin, natural andsynthetic gums such as acacia, sodium alginate, alginic acid, otheralginates, powdered tragacanth, guar gum, cellulose and its derivatives(e.g., ethyl cellulose, cellulose acetate, carboxymethyl cellulosecalcium, sodium carboxymethyl cellulose), polyvinyl pyrrolidone, methylcellulose, pre-gelatinized starch, hydroxypropyl methyl cellulose,microcrystalline cellulose, and mixtures thereof.

Lubricants which can be used to form compositions and dosage forms ofthe invention include, but are not limited to, calcium stearate,magnesium stearate, mineral oil, light mineral oil, glycerin, sorbitol,mannitol, polyethylene glycol, other glycols, stearic acid, sodiumlauryl sulfate, talc, hydrogenated vegetable oil (e.g., peanut oil,cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil, andsoybean oil), zinc stearate, ethyl oleate, ethylaureate, agar, ormixtures thereof. Additional lubricants include, for example, a syloidsilica gel, a coagulated aerosol of synthetic silica, or mixturesthereof. A lubricant can optionally be added, in an amount of less thanabout 1 weight percent of the composition.

Lubricants can be also be used in conjunction with tissue barriers whichinclude, but are not limited to, polysaccharides, polyglycans,seprafilm, interceed and hyaluronic acid.

Disintegrants may be used in the compositions of the invention toprovide tablets that disintegrate when exposed to an aqueousenvironment. Too much of a disintegrant may produce tablets which maydisintegrate in the bottle. Too little may be insufficient fordisintegration to occur and may thus alter the rate and extent ofrelease of the active ingredient(s) from the dosage form. Thus, asufficient amount of disintegrant that is neither too little nor toomuch to detrimentally alter the release of the active ingredient(s) maybe used to form the dosage forms of the compounds disclosed herein. Theamount of disintegrant used may vary based upon the type of formulationand mode of administration, and may be readily discernible to those ofordinary skill in the art. About 0.5 to about 15 weight percent ofdisintegrant, or about 1 to about 5 weight percent of disintegrant, maybe used in the pharmaceutical composition. Disintegrants that can beused to form compositions and dosage forms of the invention include, butare not limited to, agar-agar, alginic acid, calcium carbonate,microcrystalline cellulose, croscarmellose sodium, crospovidone,polacrilin potassium, sodium starch glycolate, potato or tapioca starch,other starches, pre-gelatinized starch, other starches, clays, otheralgins, other celluloses, gums or mixtures thereof.

Examples of suitable fillers for use in the compositions and dosageforms disclosed herein include, but are not limited to, talc, calciumcarbonate (e.g., granules or powder), microcrystalline cellulose,powdered cellulose, dextrates, kaolin, mannitol, silicic acid, sorbitol,starch, pre-gelatinized starch, and mixtures thereof.

When aqueous suspensions and/or elixirs are desired for oraladministration, the active ingredient therein may be combined withvarious sweetening or flavoring agents, coloring matter or dyes and, ifso desired, emulsifying and/or suspending agents, together with suchdiluents as water, ethanol, propylene glycol, glycerin and variouscombinations thereof.

The tablets can be uncoated or coated by known techniques to delaydisintegration and absorption in the gastrointestinal tract and therebyprovide a sustained action over a longer period. For example, a timedelay material such as glyceryl monostearate or glyceryl distearate canbe employed. Formulations for oral use can also be presented as hardgelatin capsules wherein the active ingredient is mixed with an inertsolid diluent, for example, calcium carbonate, calcium phosphate orkaolin, or as soft gelatin capsules wherein the active ingredient ismixed with water or an oil medium, for example, peanut oil, liquidparaffin or olive oil.

In one embodiment, the composition may include a solubilizer to ensuregood solubilization and/or dissolution of the compound of the presentinvention and to minimize precipitation of the compound of the presentinvention. This can be especially important for compositions fornon-oral use, e.g., compositions for injection. A solubilizer may alsobe added to increase the solubility of the hydrophilic drug and/or othercomponents, such as surfactants, or to maintain the composition as astable or homogeneous solution or dispersion.

The composition can further include one or more pharmaceuticallyacceptable additives and excipients. Such additives and excipientsinclude, without limitation, detackifiers, anti-foaming agents,buffering agents, polymers, antioxidants, preservatives, chelatingagents, viscomodulators, tonicifiers, flavorants, colorants, odorants,opacifiers, suspending agents, binders, fillers, plasticizers,lubricants, and mixtures thereof. A non-exhaustive list of examples ofexcipients includes monoglycerides, magnesium stearate, modified foodstarch, gelatin, microcrystalline cellulose, glycerin, stearic acid,silica, yellow beeswax, lecithin, hydroxypropylcellulose, croscarmellosesodium, and crospovidone.

The compositions described herein can also be formulated asextended-release, sustained-release or time-release such that one ormore components are released over time. Delayed release can be achievedby formulating the one or more components in a matrix of a variety ofmaterials or by microencapsulation. The compositions can be formulatedto release one or more components over a time period of 4, 6, 8, 12, 16,20, or 24 hours. The release of the one or more components can be at aconstant or changing rate.

Using the controlled release dosage forms provided herein, the one ormore cofactors can be released in its dosage form at a slower rate thanobserved for an immediate release formulation of the same quantity ofcomponents. In some embodiments, the rate of change in the biologicalsample measured as the change in concentration over a defined timeperiod from administration to maximum concentration for an controlledrelease formulation is less than about 80%, 70%, 60%, 50%, 40%, 30%,20%, or 10% of the rate of the immediate release formulation.Furthermore, in some embodiments, the rate of change in concentrationover time is less than about 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10%of the rate for the immediate release formulation.

In some embodiments, the rate of change of concentration over time isreduced by increasing the time to maximum concentration in a relativelyproportional manner. For example, a two-fold increase in the time tomaximum concentration may reduce the rate of change in concentration byapproximately a factor of 2. As a result, the one or more cofactors maybe provided so that it reaches its maximum concentration at a rate thatis significantly reduced over an immediate release dosage form. Thecompositions of the present invention may be formulated to provide ashift in maximum concentration by 24 hours, 16 hours, 8 hours, 4 hours,2 hours, or at least 1 hour. The associated reduction in rate of changein concentration may be by a factor of about 0.05, 0.10, 0.25, 0.5 or atleast 0.8. In certain embodiments, this is accomplished by releasingless than about 30%, 50%, 75%, 90%, or 95% of the one or more cofactorsinto the circulation within one hour of such administration.

Optionally, the controlled release formulations exhibit plasmaconcentration curves having initial (e.g., from 2 hours afteradministration to 4 hours after administration) slopes less than 75%,50%, 40%, 30%, 20% or 10% of those for an immediate release formulationof the same dosage of the same cofactor.

In some embodiments, the rate of release of the cofactor as measured indissolution studies is less than about 80%, 70%, 60% 50%, 40%, 30%, 20%,or 10% of the rate for an immediate release formulation of the samecofactor over the first 1, 2, 4, 6, 8, 10, or 12 hours.

The controlled release formulations provided herein can adopt a varietyof formats. In some embodiments, the formulation is in an oral dosageform, including liquid dosage forms (e.g., a suspension or slurry), andoral solid dosage forms (e.g., a tablet or bulk powder), such as, butnot limited to those, those described herein.

The controlled release tablet of a formulation disclosed herein can beof a matrix, reservoir or osmotic system. Although any of the threesystems is suitable, the latter two systems can have more optimalcapacity for encapsulating a relatively large mass, such as for theinclusion of a large amount of a single cofactor, or for inclusion of aplurality of cofactors, depending on the genetic makeup of theindividual. In some embodiments, the slow-release tablet is based on areservoir system, wherein the core containing the one or more cofactorsis encapsulated by a porous membrane coating which, upon hydration,permits the one or more cofactors to diffuse through. Because thecombined mass of the effective ingredients is generally in gramquantity, an efficient delivery system can provide optimal results.

Thus, tablets or pills can also be coated or otherwise compounded toprovide a dosage form affording the advantage of prolonged action. Forexample, the tablet or pill can comprise an inner dosage an outer dosagecomponent, the latter being in the form of an envelope over the former.The two components can be separated by an enteric layer which serves toresist disintegration in the stomach and permits the inner component topass intact into the duodenum or to be delayed in release. A variety ofmaterials can be used for such enteric layers or coatings such materialsincluding a number of polymeric acids and mixtures of polymeric acidswith such materials as shellac, cetyl alcohol and cellulose acetate. Insome embodiments, a formulation comprising a plurality of cofactors mayhave different cofactors released at different rates or at differenttimes. For example, there can be additional layers of cofactorsinterspersed with enteric layers.

Methods of making sustained release tablets are known in the art, e.g.,see U.S. Patent Publications 2006/051416 and 2007/0065512, or otherreferences disclosed herein. Methods such as described in U.S. Pat. Nos.4,606,909, 4,769,027, 4,897,268, and 5,395,626 can be used to preparesustained release formulations of the one or more cofactors determinedby the genetic makeup of an individual. In some embodiments, theformulation is prepared using OROS® technology, such as described inU.S. Pat. Nos. 6,919,373, 6,923,800, 6,929,803, and 6,939,556. Othermethods, such as described in U.S. Pat. Nos. 6,797,283, 6,764,697, and6,635,268, can also be used to prepare the formulations disclosedherein.

In some embodiments, the compositions can be formulated in a foodcomposition. For example, the compositions can be a beverage or otherliquids, solid food, semi-solid food, with or without a food carrier.For example, the compositions can include a black tea supplemented withany of the compositions described herein. The composition can be a dairyproduct supplemented any of the compositions described herein. In someembodiments, the compositions can be formulated in a food composition.For example, the compositions can comprise a beverage, solid food,semi-solid food, or a food carrier.

In some embodiments, liquid food carriers, such as in the form ofbeverages, such as supplemented juices, coffees, teas, sodas, flavoredwaters, and the like can be used. For example, the beverage can comprisethe formulation as well as a liquid component, such as various deodorantor natural carbohydrates present in conventional beverages. Examples ofnatural carbohydrates include, but are not limited to, monosaccharidessuch as, glucose and fructose; disaccharides such as maltose andsucrose; conventional sugars, such as dextrin and cyclodextrin; andsugar alcohols, such as xylitol and erythritol. Natural deodorant suchas taumatin, stevia extract, levaudioside A, glycyrrhizin, and syntheticdeodorant such as saccharin and aspartame may also be used. Agents suchas flavoring agents, coloring agents, and others can also be used. Forexample, pectic acid and the salt thereof, alginic acid and the saltthereof, organic acid, protective colloidal adhesive, pH controllingagent, stabilizer, a preservative, glycerin, alcohol, or carbonizingagents can also be used. Fruit and vegetables can also be used inpreparing foods or beverages comprising the formulations discussedherein.

Alternatively, the compositions can be a snack bar supplemented with anyof the compositions described herein. For example, the snack bar can bea chocolate bar, a granola bar, or a trail mix bar. In yet anotherembodiment, the present dietary supplement or food compositions areformulated to have suitable and desirable taste, texture, and viscosityfor consumption. Any suitable food carrier can be used in the presentfood compositions. Food carriers of the present invention includepractically any food product. Examples of such food carriers include,but are not limited to food bars (granola bars, protein bars, candybars, etc.), cereal products (oatmeal, breakfast cereals, granola,etc.), bakery products (bread, donuts, crackers, bagels, pastries,cakes, etc.), beverages (milk-based beverage, sports drinks, fruitjuices, alcoholic beverages, bottled waters), pastas, grains (rice,corn, oats, rye, wheat, flour, etc.), egg products, snacks (candy,chips, gum, chocolate, etc.), meats, fruits, and vegetables. In anembodiment, food carriers employed herein can mask the undesirable taste(e.g., bitterness). Where desired, the food composition presented hereinexhibit more desirable textures and aromas than that of any of thecomponents described herein. For example, liquid food carriers may beused according to the invention to obtain the present food compositionsin the form of beverages, such as supplemented juices, coffees, teas,and the like. In other embodiments, solid food carriers may be usedaccording to the invention to obtain the present food compositions inthe form of meal replacements, such as supplemented snack bars, pasta,breads, and the like. In yet other embodiments, semi-solid food carriersmay be used according to the invention to obtain the present foodcompositions in the form of gums, chewy candies or snacks, and the like.

The dosing of the combination compositions can be administered about,less than about, or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ormore times a daily. A subject can receive dosing for a period of about,less than about, or greater than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14 or more days, weeks or months. A unit dose can be afraction of the daily dose, such as the daily dose divided by the numberof unit doses to be administered per day. A unit dose can be a fractionof the daily dose that is the daily dose divided by the number of unitdoses to be administered per day and further divided by the number ofunit doses (e.g. tablets) per administration. The number of unit dosesper administration may be about, less than about, or more than about 1,2, 3, 4, 5, 6, 7, 8, 9, 10, or more. The number of doses per day may beabout, less than about, or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9,10, or more. The number of unit doses per day may be determined bydividing the daily dose by the unit dose, and may be about, less thanabout, or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 6, 17, 18, 19, 20, or more unit doses per day. For example, a unitdose can be about ½, ⅓, ¼, ⅕, ⅙, 1/7, ⅛, 1/9, 1/10. A unit dose can beabout one-third of the daily amount and administered to the subjectthree times daily. A unit dose can be about one-half of the daily amountand administered to the subject twice daily. A unit dose can be aboutone-fourth of the daily amount with two unit doses administered to thesubject twice daily. In some embodiments, a unit dose comprises about,less than about, or more than about 50 mg resveratrol. In someembodiments, a unit dose comprises about, less than about, or more thanabout 550 mg leucine. In some embodiments, a unit dose comprises about,less than about, or more than about 200 mg of one or more leucinemetabolites. In some embodiments, a unit dose (e.g. a unit dosecomprising leucine) is administered as two unit doses two times per day.In some embodiments, a unit dose (e.g. a unit dose comprising one ormore leucine metabolites, such as HMB) is administered as one unit dosetwo timer per day.

Compositions disclosed herein can further comprise a flavorant and canbe a solid, liquid, gel or emulsion.

Methods

The subject application provides methods of increasing sirtuin pathwayoutput (including AMPK, a signaling molecule in the sirtuin pathway) ina subject using a selective PDE inhibitor. As described herein, theoutput of the sirtuin pathway can be characterized at the molecularlevel or by a resulting physiological effect. In some embodiments, theinvention provides for methods of increasing fatty acid oxidation in asubject comprising the administration of a composition as disclosedherein to the subject. In various embodiments of the invention, acomposition is administered to the subject in an amount that deliverssynergizing amounts of one or more branched amino acids or a metabolitethereof, such as leucine or HMB, and a PDE 5 inhibitor, such assildenafil or icariin, sufficient to increase fatty acid oxidationwithin the cells of the subject.

The methods described herein can be useful for a variety ofapplications. These applications include (a) an increase insirtuin-pathway output, (b) an increase in mitochondrial biogenesis, (c)an increase in the formation of new mitochondria, (d) an increase inmitochondrial functions, (e) an increase in fatty acid oxidation, (f) anincrease in heat generation, (g) an increase in insulin sensitivity, (h)an increase in glucose uptake, (i) an increase in vasodilation, (j) adecrease in weight, (k) a decrease in adipose volume, (1) a decrease ininflammatory response or markers in a subject, and (m) an increase inirisin production. Any of these applications can be achieved byadministering one or more compositions described herein.

Accordingly, the invention provides a method for administering acomposition comprising (a) one or more types of branched amino acidsand/or metabolites thereof and (b) a selective PDE inhibitor present ina sub-therapeutic amount, wherein the composition is synergisticallyeffective in increasing the sirtuin-pathway output by at least about 5fold as compared to that of component (a) or (b) when used alone.

The output of the pathways can be measured using one or more methods,disclosed herein and/or known in the art. For example, fatty acidoxidation can be determined by measuring oxygen consumption, or3H-labeled palmitate oxidation. Mitochondrial biogenesis can be measuredusing a mitochondrial probe by using fluorescence. AMPK activity can bedetermined by measuring AMPK phosphorylation via an ELISA assay or byWestern blot. Sirt1 activity can be determined by measuringdeacetylation of a substrate, which can be detected using a fluorophore.

An increase in sirt1, sirt2, or sirt3 is observed by applying acorresponding substrate in a deacylation assay conducted in vitro. Thesubstrate for measuring SIRT1 activity can be any substrate known in theart (for example a peptide containing amino acids 379-382 of human p53(Arg-His-Lys-Lys[Ac]). The substrate for measuring SIRT3 activity can beany substrate known in the art (for example a peptide containing aminoacids 317-320 of human p53 (Gln-Pro-Lys-Lys[Ac])). In some instances,the increase in sirt activity in one or more assays conducted in thepresence of one or more combination compositions described hereinresults in an activity increase of at least about 1, 2, 3, 5, or 10fold, as compared to the activity measured in the presence of only onecomponent of the combination compositions. For example, the use of acombination composition comprising (a) a sirtuin pathway activator (suchas sildenafil) and (b) a branched chain amino acid or metabolite thereof(such as HMB) results in an increase in sirt3 activity by at least about5 fold as compared to the activity measured in the presence of (a) or(b) alone. Also, the use of a subject composition results in an increasein sirt1 activity that is 1.5, 2, 5 or 10 fold greater than the activitymeasured in the presence of only one component of the composition.

The invention provides a method for administering a compositioncomprising: (a) one or more types of branched amino acids and/ormetabolites thereof, and (b) a selective PDE inhibitor, wherein thetarget or achieved circulating molar ratio of component (a) to (b) in asubject administered said composition is greater than about 100,000,200,000, or 500,000, and wherein the composition when administered to asubject in need thereof synergistically enhances energy metabolism asmeasured by a decrease in weight gain of a subject, a decrease invisceral adipose volume of a subject, an increase in fat oxidation of asubject, an increase in insulin sensitivity of a subject, an increase ofglucose uptake in muscle of a subject, a decrease in inflammationmarkers, an increase in vasodilatation, and/or an increase in bodytemperature.

The invention provides a method for administering a food compositioncomprising: (a) one or more types of branched amino acids and/ormetabolites thereof; (b) a selective PDE inhibitor (e.g., sildenafil oricariin), wherein (a) and (b) are present in an amount thatsynergistically effect a decrease in weight gain of a subject, adecrease in visceral adipose volume of a subject, an increase in fatoxidation of a subject, an increase in insulin sensitivity of a subject,an increase of glucose uptake in muscle of a subject, an increase invasodilatation, a decrease in oxidative stress, a decrease ininflammatory stress, and/or an increase in body temperature; and (c) afood carrier.

The invention provides a method for administering a compositioncomprising: a combination of (a) one or more types of branched aminoacids and/or metabolites thereof; and (b) a PDE-5 inhibitor, wherein thecomposition is substantially free of non-branched amino acids, whereinthe combination when administered to a subject in need thereof enhancesmitochondrial biogenesis to a greater degree as compared toadministering to a subject component (a) or component (b) alone, andwherein the enhanced mitochondrial biogenesis is measured by a decreasein weight of a subject, a decrease in visceral adipose volume of asubject, an increase in fat oxidation of a subject, an increase ininsulin sensitivity of a subject, an increase of glucose uptake inmuscle of a subject, an increase in vasodilatation, a decrease inoxidative stress, a decrease in inflammatory stress, and/or an increasein body temperature. For some embodiment, the amount of (a) and theamount of (b) are synergistic.

The invention provides a method for administering a compositioncomprising: a combination of (a) one or more types of branched aminoacids and/or metabolites thereof; and (b) a PDE-5 inhibitor, wherein thecomposition is substantially free of non-branched amino acids, whereinthe combination when administered to a subject in need thereof enhancesmitochondrial biogenesis to a greater degree as compared toadministering to a subject component (a) or component (b) alone, andwherein the enhanced mitochondrial biogenesis is measured by a decreasein weight of a subject, a decrease in visceral adipose volume of asubject, an increase in fat oxidation of a subject, an increase ininsulin sensitivity of a subject, an increase of glucose uptake inmuscle of a subject, an increase in vasodilatation, a decrease inoxidative stress, a decrease in inflammatory stress, and/or an increasein body temperature. In some embodiment, the amount of (a) and theamount of (b) are synergistic.

The invention provides for a method of enhancing fat oxidation in asubject in need thereof comprising administering to the subject any ofthe compositions described herein over a time period, wherein the fatoxidation in the subject is increased over the time period. The fatoxidation can be increased by about or greater than about 5, 10, 15, 20,50, 100, 200, or 500%.

The invention provides for a method of reducing an inflammatory responsein a subject in need thereof comprising administering to the subject acomposition any of the compositions described herein over a time period,wherein the inflammatory response in the subject is reduced over thetime period. The inflammatory response can be decreased by about orgreater than about 5, 10, 15, 20, 50, or 100%.

Inflammatory marker and cytokine levels, including but not limited toIL-6, adiponectin, TNF-α and CRP levels in plasma can determined byimmune assays, such as ELISA (Assay Designs, Ann Arbor, Mich.; LincoResearch, St. Charles, Mo.; and Bioscience, San Diego, Calif.).

The invention provides for a method of increasing or maintaining bodytemperature in a subject comprising administering to the subject acomposition any of the compositions described herein over a time period,wherein the body temperature in the subject is increased over the timeperiod. The body temperature can be increased by about or greater thanabout 1, 2, 3, 4, 5, 10, 15, or 20%.

The invention provides for a method of inducing vasodilatationcomprising administering to the subject a composition of any of thecompositions described herein over a time period, wherein thevasodilation in the subject is induced over the time period. Thevasodilation of blood vessels can be increased by about or greater thanabout 1, 2, 3, 5, 10, 20, 50, or 100%. The vasodilation can be measuredby optically, by measuring vasorestriction, or by a variety of othertechniques. These techniques include the invasive forearm technique, thebrachial artery ultrasound technique, and pulse wave analysis. Methodsfor measuring vasodilation are described in Lind et al., “Evaluation offour different methods to measure endothelium-dependent vasodilation inthe human peripheral circulation,” Clinical Science 2002, 102, 561-567.

The invention provides for a method of increasing irisin production,comprising administering to the subject any of the compositionsdescribed herein, wherein irisin production in the subject increasesover a time period. In some embodiments, the increase in irisinproduction (or in an indicator providing evidence thereof) is anincrease of about, or more than about 5%, 10%, 20%, 30%, 40%, 50%, 60%,70%, 80%, 90%, 100%, 125%, 150%, 175%, 200%, or more. In someembodiments, the increase in irisin production (or in an indicatorproviding evidence thereof) is an increase of about, or more than about1-fold, 3-fold, 5-fold, 6-fold, 8-fold, 10-fold, 15-fold, 20-fold,50-fold, or more. In some embodiments, the increase in irisin productionis evidenced by an increase in FNDCS expression (e.g. as measured frommRNA and/or protein level). In some embodiments, the increase in irisinproduction is evidenced by an increase in one or more indicia of fatcell browning (e.g. fatty acid oxidation, and/or an increase inexpression of one or more brown fat selective genes in adipose tissue).Non-limiting examples of brown fat selective genes include Ucp1, Cidea,Prdm16, and Ndufs. In some embodiments, the increase in irisinproduction is evidenced by increased secretion of irisin from the cell(e.g. as measured from media in which the cell is cultured, or fromcirculating plasma in a subject). Increases in gene levels can bemeasured directly (e.g. changes in mRNA or protein levels) or indirectly(changes in effects associated with expression increase, such as anincreased expression of a downstream gene). Methods for detectingchanges in gene expression level are known in the art, and include,without limitation, methods for the detection of mRNA (e.g. RT-PCR,Northern blot, and microarray hybridization), detection of proteinproducts (e.g. Western blot, and ELISA), a detection of one or moreactivities of the translated protein (e.g. enzyme activity assays).

The invention provides for a method of treating a diabetic subject,e.g., a subject with Type I diabetes, Type II diabetes, and/ordiet-induced diabetes, comprising administering to the subject any ofthe compositions described herein over a time period. The diabetes maybe characterized by reduced insulin levels, insulin resistance, or acombination of both. In some embodiments, the administering is effectiveto improve a symptom of diabetes in the subject. For example,administration of the composition can improve insulin sensitivity in asubject. Type I diabetes may be characterized by reduced insulinproduction as compared to a subject without Type I diabetes.Administration of a composition described herein can improve thesensitivity of a subject with Type I diabetes (e.g., having reducedinsulin) to the insulin that is produced by or administered to thesubject. Type II diabetes may be characterized by reduced sensitivity toinsulin. Accordingly, administration of a composition described hereincan improve insulin sensitivity in a subject with Type II diabetes.

An exemplary symptom of diabetes is reduced insulin sensitivity. Insulinsensitivity can be determined by any means known in the art. Forexample, insulin sensitivity can be determined by measuring bloodglucose levels in a subject, in some cases over a period of time,following administration of a bolus of insulin. Subjects with reducedinsulin sensitivity typically exhibit an attenuated drop in bloodglucose levels following insulin administration, as compared to subjectwith normal insulin sensitivity. Administration of a compositiondescribed herein can increase insulin sensitivity in a subject.Administration of a composition described herein can increase insulinsensitivity in the subject, as compared to, e.g., the level of insulinsensitivity in the subject prior to the administration. Insulinsensitivity can be increased by about or greater than about 1, 2, 3, 5,10, 20, 50, 100, or 200%, as compared to the level of insulinsensitivity in the subject prior to administration of the composition.

Another exemplary symptom of diabetes is reduced glucose tolerance.Glucose tolerance can be determined by any means known in the art. Forexample, glucose tolerance can be determined by measuring blood glucoselevels in a subject, in some cases over a period of time, followingadministration of a bolus of glucose. Subjects with reduced glucosetolerance typically exhibit elevated blood glucose levels and/or slowerclearance of glucose from the blood as compared to subjects with normalglucose tolerance. Administration of a composition described herein canincrease glucose tolerance in a subject. Administration of a compositiondescribed herein can increase glucose tolerance in the subject, ascompared to, e.g., the level of glucose tolerance in the subject priorto the administration. Glucose tolerance can be increased by about orgreater than about 1, 2, 3, 5, 10, 20, 50, 100, or 200%, as compared to,e.g., the level of glucose tolerance in the subject prior to theadministration.

Another symptom of diabetes is elevated post-prandial or fasting bloodglucose levels. Blood glucose levels can be determined by any meansknown in the art. For example, blood glucose levels can be determinedby, e.g., glucose monitor. Elevated blood glucose can be, e.g., anincrease in blood glucose levels in a subject with diabetes as comparedto blood glucose levels in a subject or control population withoutdiabetes. Administration of a composition described herein can reduceblood glucose levels (e.g., post-prandial and/or fasting blood glucose)in a subject. Administration of a composition described herein canreduce blood glucose levels (e.g., post-prandial and/or fasting bloodglucose) in the subject, as compared to, e.g., the level of bloodglucose in the subject prior to the administration. Administration of acomposition described herein can reduce blood glucose levels by about orgreater than about 1, 2, 3, 5, 10, 20, 50, 60, 70, 80, 90, or 100% ascompared to the blood glucose levels in the subject prior to theadministration. Administration of a composition described herein canreduce blood glucose levels to normal levels, e.g., levels found in acontrol population that does not have diabetes.

Another symptom of diabetes is elevated Homeostatic Assessment ofInsulin Resistance (HOMA_(IR)). HOMA_(IR) can be determined by any meansknown in the art, for example, by the following equation:HOMA_(IR)=[Insulin (uU/mL)×glucose (mM)]/22.5. Administration of acomposition described herein can reduce HOMA_(IR) levels in the subject.Elevated HOMA_(IR) can be, e.g., an increase in HOMA_(IR) levels in asubject with diabetes as compared to HOMA_(IR) levels in a subject orcontrol population without diabetes. Administration of a compositiondescribed herein can reduce HOMA_(IR) levels in a subject.Administration of a composition described herein can reduce HOMA_(IR)levels in the subject, as compared to, e.g., the HOMA_(IR) levels in thesubject prior to administration of a composition described herein.Administration of the composition can decrease HOMA_(IR) levels by aboutor greater than about 1, 2, 3, 5, 10, 20, 50, 60, 70, 80, 90, or 100%,as compared to the HOMA_(IR) levels in the subject prior toadministration of the composition. HOMA_(IR) levels can be decreased tonormal levels, e.g., levels found in a control population that does nothave diabetes.

Another symptom of diabetes is elevated liver mass. Liver mass can beestimated by any means known in the art, for example, by imaging or bybiopsy. Elevated liver mass can be, e.g., an increase liver mass in asubject with diabetes as compared to liver mass in a subject or controlpopulation without diabetes. Administration of a composition describedherein can reduce liver mass in the subject. Administration of acomposition described herein can decrease liver mass in the subject ascompared to, e.g., the liver mass of the subject prior to administrationof a composition described herein. Administration of the composition candecrease liver mass by about or greater than about 1, 2, 3, 5, 10, 20,50, 60, 70, 80, 90, or 100%, as compared to the liver mass of thesubject prior to administration of the composition. Administration ofthe composition can decrease liver mass of the subject to normal, e.g.,to an average liver mass found in a control population that does nothave diabetes.

Another symptom of diabetes is elevated inflammation. Inflammation in asubject can be estimated by any means known in the art, for example, byanalysis of markers associated with inflammation in a subject or in abiological sample obtained from a subject. Markers associated withinflammation are known in the art, and include, e.g., inflammatory cellstypes, protein receptors, inflammatory molecules, and other indicatorsinvolved in inflammatory pathways. Exemplary markers associated withinflammation include, but are not limited to cytokines, IL-6,adiponectin, MCP-1 and C-reactive protein (CRP). The biological samplecan be, e.g., whole blood, plasma, serum, saliva, sputum, urine, feces,skin, hair, or tissue biopsy. The biological sample can be obtained byany means known in the art. The markers can be detected and/or assessedby any means known in the art, for example, by imaging, byimmunofluorescence, by immunohistochemistry, by gene expressionanalysis, by in situ hybridization, by RNase protection assay, byreporter assay, by ELISA, or by any other method. Administration of acomposition described herein can reduce inflammation in a subject.Administration of a composition described herein can reduce inflammationin the subject, as compared to, e.g., inflammation levels in the subjectprior to the administration. Elevated inflammation can be, e.g., anincrease in inflammation levels in a subject with diabetes as comparedto inflammation levels in a subject or control population withoutdiabetes. Administration of a composition described herein can reduce byabout or greater than about 1, 2, 3, 5, 10, 20, 50, 60, 70, 80, 90, or100%, as compared to inflammation levels in the subject prior to theadministration. Administration of a composition described herein canreduce inflammation in the subject to normal levels, e.g., to averageinflammation levels found in a control population that does not havediabetes.

In some embodiments, insulin signaling can also be measured. Insulinsignaling can be measured by measuring total and phosphorylated Akt,GSK-3β, IGF-1R, IR, IRS-1, p70S6K and PRAS40 in tissue lysates via theLuminex Kits “Akt Pathway Total 7-Plex Panel” (Cat# LH00002) and “AktPathway Phospho 7-Plex Panel” (Cat# LH00001) from Invitrogen LifeScience.

In some embodiments, a branched chain amino acid (or a metabolitethereof) and/or a selective PDE inhibitor are administered in an amountthat reduces the therapeutically effective dose of metformin for asubject. In some embodiments, the therapeutically effective dose ofmetformin is reduced by about or more than about 50%, 60%, 70%, 80%,90%, 95%, 97.5%, 99.9%, 99.99%, or more. In some embodiments,administration of compositions of the invention reduces body fat (e.g.visceral fat) by about or more than about 5%, 10%, 15%, 20%, 25%, 50%,or more.

The subject application also provides methods of increasingmitochondrial biogenesis in a subject comprising the administration of acomposition disclosed herein to a subject. In various embodiments of theinvention, a composition is administered to the subject in an amountthat delivers synergizing amount of a selective PDE inhibitor sufficientto increase mitochondrial biogenesis within the cells of the subject.Another embodiment provides for the administration of a compositioncomprising synergizing amounts of leucine and a PDE inhibitor (e.g.,PDE-5 inhibitor) to the subject in an amount sufficient to increasemitochondrial biogenesis within the cells of the subject. Yet otherembodiments provide for the administration of a composition comprisingsynergizing amounts of leucine, PDE inhibitor (e.g., PDE-5 inhibitor),and resveratrol to a subject in an amount sufficient to increasemitochondrial biogenesis in the subject. Mitochondrial biogenesis andfat oxidation may be induced in various cells, including muscle cellsand adipocytes.

Another aspect of the invention provides methods of reducing weight gainor reducing adipose volume in a subject comprising the administration ofcompositions disclosed herein. Body weight can be measured with acalibrated scale and height measured with a wall-mounted stadiometer,and body mass index can be calculated via standard equation (kg/m2). Fatmass can be assessed via dual-energy X-ray absorptiometry at baseline,and 12 and 24 weeks. A LUNAR Prodigy dual-energy X-ray absorptiometrysystem (GE Healthcare, Madison, Wis.), or any other X-ray absorptiometrysystem known in the art, can be maintained and calibrated for use. Aspine phantom can be assessed every day to determine whether any driftin the machine occurred, followed by a daily calibration block.

In this aspect of the invention, a composition is administered to thesubject in an amount that delivers synergizing amount of a selective PDEinhibitor in combination with one or more of leucine, HMB, andresveratrol sufficient to reduce weight gain in a subject.

Administration of compositions disclosed herein that increase SIRT1 andSIRT3 activity may be useful in any subject in need of metabolicactivation of adipocytes or one or more of their muscles, e.g., skeletalmuscle, smooth muscle or cardiac muscle or muscle cells thereof. Asubject may be a subject having cachexia or muscle wasting. IncreasingSIRT3 activity may also be used to increase or maintain bodytemperature, e.g., in hypothermic subjects and increasing SIRT1 activityis beneficial for treating diabetes (type 2 diabetes) and impairedglucose tolerance and reducing inflammatory responses in a subject.

Increasing SIRT3 activity may also be used for treating or preventingcardiovascular diseases, reducing blood pressure by vasodilation,increasing cardiovascular health, and increasing the contractilefunction of vascular tissues, e.g., blood vessels and arteries (e.g., byaffecting smooth muscles). Generally, activation of SIRT3 may be used tostimulate the metabolism of adipocytes or any type of muscle, e.g.,muscles of the gut or digestive system, or the urinary tract, andthereby may be used to control gut motility, e.g., constipation, andincontinence. SIRT3 activation may also be useful in erectiledysfunction. It may also be used to stimulate sperm motility, e.g., andbe used as a fertility drug. Other embodiments in which it would beuseful to increase SIRT3 include repair of muscle, such as after asurgery or an accident, increase of muscle mass; and increase ofathletic performance.

Thus the invention provides methods in which beneficial effects areproduced by contacting one or more muscle cells with an agent thatincreases the protein or activity level of SIRT3 in the cell. Thesemethods effectively facilitate, increase or stimulate one or more of thefollowing: mimic the benefits of calorie restriction or exercise in themuscle cell, increase mitochondrial biogenesis or metabolism, increasemitochondrial activity and/or endurance in the muscle cell, sensitizethe muscle cell to glucose uptake, increase fatty acid oxidation in themuscle cell, decrease reactive oxygen species (ROS) in the muscle cell,increase PGC-la and/or UCP3 and/or GLUT4 expression in the muscle cell,and activate AMP activated protein kinase (AMPK) in the muscle cell.Various types of muscle cells can be contacted in accordance with theinvention. In some embodiments, the muscle cell is a skeletal musclecell. In certain embodiments, the muscle cell is a cell of a slow-twitchmuscle, such as a soleus muscle cell.

Resting metabolic rate (RMR)/Substrate Oxidation is measured by indirectcalorimetry using the open circuit technique between the hours of 6 AMand 10 AM after a 12-hour fast and 48-hour abstention from exerciseutilizing a SensorMedics Vmax 29n metabolic cart (Sensor Medics,Anaheim, Calif.). Following a urinary void, the participant restsquietly for 30 minutes in an isolated room with temperature controlled(21-24° C.) environment. The subject is then placed in a ventilated hoodfor a minimum of 30 minutes, until steady state is achieved. Criteriafor a valid measurement can be a minimum of 15 minutes of steady state,with steady state determined as less than 10% fluctuation in minuteventilation and oxygen consumption and less than 5% fluctuation inrespiratory quotient. Metabolic rate is calculated using the Weirequation, RQ is calculated as CO₂ production/O₂ consumption, andsubstrate oxidation is calculated from RQ after correction for urinarynitrogen losses.

Glucose uptake can be measured using in vivo or in vitro techniques. Forexample, glucose uptake can be measured in vivo using a PET scan inconjunction with labeled glucose or glucose analog. Measurements ofglucose uptake can be quantified from the PET scan or by any othertechnique known in the art. In some embodiments, the glucose uptake canbe measured by quantitation of exogenously administered18-F-deoxyglucose uptake via PET.

ROS/Oxidative Stress can be measured by drawing blood into EDTA-treatedtubes, centrifuging to separate plasma, and aliquoting samples forindividual assays. Plasma can be maintained at −80° C. under nitrogen toprevent oxidative changes prior to measurements. Plasma malonaldehyde(MDA) can be measured using a fluorometric assay, and plasma8-isoprostane F2α was measured by ELISA (Assay Designs, Ann Arbor,Mich.).

Another embodiment provides for the administration of a compositioncomprising synergizing amounts of leucine and resveratrol to the subjectin an amount sufficient to increase fatty acid oxidation within thecells of the subject. Yet other embodiments provide for theadministration of a composition comprising synergizing amounts ofleucine, HMB and resveratrol to a subject in an amount sufficient toincrease fatty acid oxidation in the subject. The leucine may be in freeamino acid form.

The compositions can be administered to a subject orally or by any othermethods. Methods of oral administration include administering thecomposition as a liquid, a solid, or a semi-solid that can be taken inthe form of a dietary supplement or a food stuff.

The compositions can be administered periodically. For example, thecompositions can be administered one, two, three, four times a day, oreven more frequent. The subject can be administered every 1, 2, 3, 4, 5,6 or 7 days. In some embodiments, the compositions are administeredthree times daily. The administration can be concurrent with meal timeof a subject. The period of treatment or diet supplementation can be forabout 1, 2, 3, 4, 5, 6, 7, 8, or 9 days, 1 week or longer, 2 weeks orlonger, six weeks or longer, 1-11 months or longer, 1 year or longer, 2years or longer, or 5 years or longer. In some embodiments of theinvention, the dosages that are administered to a subject can change orremain constant over the period of treatment. For example, the dailydosing amounts can increase or decrease over the period ofadministration.

The compositions can be therapeutically effective over a prolonged timeperiod, such that the beneficial effects are maintained. The beneficialeffects can be maintained by administration of the compositionsdescribed herein for a period of at least about 4, 6, 8, 10, or 12weeks, or at least about 4, 6, 12, 24, 48, or 72 months.

The compositions can be administered to a subject such that the subjectis administered a selected total daily dose of the composition, asdescribed herein. For example, the total daily dose of the compositioncan include about 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, 40, 60, 80, or 100 mgof sildenafil.

In some embodiments, a selected dose of a composition can beadministered to a subject such that the subject achieves a desiredcirculating level of the composition, as described herein. For example,the desired circulating level of the composition can be about 0.1, 0.5,1, 2, 5, 10 nM or more of sildenafil and the desired circulating levelof the composition can be at least about 0.25, 0.5, 0.75, 1 mM or moreof leucine. The selected dose can be chosen based on the characteristicsof the subject, such as weight, height, ethnicity, or genetics.

In another aspect, the invention provides for a method for increasingenergy metabolism in a subject, comprising administering a compositiondescribed herein, such as one comprising a selective PDE inhibitor to asubject in need for a period of time in which the subject's energymetabolism is increased. The invention also provides for a method forenhancing fat oxidation in a subject in need thereof comprisingadministering a composition described herein at least two times per dayover a time period, wherein the fat oxidation in the subject isincreased over the time period as compared to the fat oxidation in thesubject prior to said time period. The subject's energy metabolism canbe measured before treatment and after treatment to determine if thesubject's energy metabolism has increased. Alternatively, subjects canbe pooled into test and control groups, where the increase in energymetabolism is measured between groups.

The length of the period of administration and/or the dosing amounts canbe determined by a physician, a nutritionist, or any other type ofclinician. The period of time can be one, two, three, four or moreweeks. Alternatively, the period of time can be one, two, three, four,five, six or more months.

In another aspect, the invention provides for a method for increasingenergy metabolism in a subject comprising administering a compositiondescribed herein at a selected dosing level, wherein the selected dosinglevel induces a circulating level of about 0.5 mM leucine and about 1 nMsildenafil in the subject. The dosing level can be adjusted based on thesubject's characteristics, such as weight, height, ethnicity, genetics,or baseline energy metabolism level.

The physician, nutritionist, or clinician can observe the subject'sresponse to the administered compositions and adjust the dosing based onthe subject's performance or measured circulating levels of leucine, aPDE 5 inhibitor, or any other component of the composition. For example,dosing levels can be increased for subjects that show reduced effects inenergy regulation or circulating levels of a PDE 5 inhibitor or leucinebelow desired target levels.

In some embodiments, the compositions administered to a subject can beoptimized for a given subject. For example, the ratio of branched chainamino acids to a selective PDE inhibitor or the particular components ina combination composition can be adjusted. The ratio and/or particularcomponents can be selected after evaluation of the subject after beingadministered one or more compositions with varying ratios of branchedchain amino acids to a selective PDE inhibitor or varying combinationcomposition components.

In some embodiments, the methods described herein comprise administeringthe invention composition alone. However, any of the methods describedherein can comprise a combination therapy. The combination therapy cancomprise administering a composition described herein (e.g., acomposition comprising a branched chain amino acid or metabolite thereofand a PDE inhibitor) in combination with an additional therapeuticagent. The additional therapeutic agent can be, e.g., a therapeuticagent for the treatment of diabetes. As used herein, the terms“co-administration”, “administered in combination with” and theirgrammatical equivalents are meant to encompass administration of theinvention composition and additional therapeutic agent to a singlesubject, and are intended to include treatment regimens in which thecomposition and additional therapeutic agent are administered by thesame or different route of administration or at the same or differenttimes. In some embodiments the composition described herein areco-administered with one or more additional therapeutic agents. Theseterms encompass administration of the invention composition andadditional therapeutic agent to a subject so that the active ingredientsof the invention composition, additional therapeutic agent(s), and/ortheir metabolites are present in the subject at the same time. Theyinclude simultaneous administration in separate compositions,administration at different times in separate compositions, and/oradministration in a single composition in which the PDE inhibitor,branched chain amino acid, and additional therapeutic agent are present.Thus, in some embodiments, the PDE inhibitor, branched chain amino acid,and additional therapeutic agent are administered in a singlecomposition. In some embodiments, the PDE inhibitor, branched chainamino acid, and additional therapeutic agent) are admixed in the singlecomposition. Exemplary additional therapeutic agents are describedherein.

In some embodiments, the additional therapeutic agent is a biguanide. Insome instances, biguanides reduce blood and/or plasma glucose levels.Examples of biguanides include and are not limited to metformin,buformin, phenformin, proguanil or the like.

In some embodiments, the additional therapeutic agent is an incretinmimetic. In some embodiments, an incretic mimic augments pancreasresponse to ingestion of food. In some instances, administration of anincretin mimetic in combination with any of the compounds describedherein lowers blood and/or plasma glucose levels. Examples of incretinmimetics include and are not limited to exenatide (Byetta®). Onecurrently used therapy for the treatment of diabetes is a subcutaneousinjection of exenatide (Byetta®).

In some embodiments, the additional therapeutic agent is athiazolidinedione. In some instances thiazolidinediones reverse insulinresistance and lower blood and/or plasma glucose levels. Examples ofthiazolidinediones include and are not limited to Rosiglitazone(Avandia), Pioglitazone (Actos), Troglitazone (Rezulin), MCC-555,rivoglitazone, ciglitazone or the like.

In some embodiments, the additional therapeutic agent is anenteroendocrine peptide. In some embodiments, enteroendocrine peptidesreverse insulin resistance and lower blood and/or plasma glucose levels.Examples of enteroendocrine peptides that are administered as additionaltherapeutic agents include and are not limited to GLP-1 or GLP-1 analogssuch as Taspoglutide® (Ipsen), or the like.

In specific embodiments, the additional therapeutic agent inhibitsdegradation of L-cell enteroendocrine peptides. In certain embodiments,the additional therapeutic agent is a DPP-IV inhibitor. DPP-IVinhibitors suitable for use with the methods described herein includeand are not limited to(2S)-1-{2-[(3-hydroxy-1-adamantyl)amino]acetyl}pyrrolidine-2-carbonitrile(vildagliptin),(3R)-3-amino-1-[9-(trifluoromethyl)-1,4,7,8-tetrazabicyclo[4.3.0]nona-6,8-dien-4-yl]-4-(2,4,5-trifluorophenyl)butan-1-one(sitagliptin),(1S,3S,5S)-2-[(2S)-2-amino-2-(3-hydroxy-1-adamantyl)acetyl]-2-azabicyclo[3.1.0]hexane-3-carbonitrile(saxagliptin), and2-({6-[(3R)-3-aminopiperidin-1-yl]-3-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl}methyl)benzonitrile(alogliptin). Another therapy that is current standard of care for thetreatment of diabetes is metformin, or a combination of metformin andsitagliptin (Janumet®).

In some embodiments, the particular choice of compounds depends upon thediagnosis of the attending physicians and their judgment of thecondition of the individual and the appropriate treatment protocol. Thecompounds are optionally administered concurrently (e.g.,simultaneously, essentially simultaneously or within the same treatmentprotocol) or sequentially, depending upon the nature of the disease,disorder, or condition, the condition of the individual, and the actualchoice of compounds used. In certain instances, the determination of theorder of administration, and the number of repetitions of administrationof each therapeutic agent during a treatment protocol, is based on anevaluation of the disease being treated and the condition of theindividual.

In some embodiments, therapeutically-effective dosages vary when thedrugs are used in treatment combinations. Methods for experimentallydetermining therapeutically-effective dosages of drugs and other agentsfor use in combination treatment regimens are described in theliterature.

In some embodiments of the combination therapies described herein,dosages of the co-administered compounds vary depending on the type ofco-drug employed, on the specific drug employed, on the disease orcondition being treated and so forth. In addition, when co-administeredwith one or more biologically active agents, the compound providedherein is optionally administered either simultaneously with thebiologically active agent(s), or sequentially. In certain instances, ifadministered sequentially, the attending physician will decide on theappropriate sequence of therapeutic compound described herein incombination with the additional therapeutic agent.

The multiple therapeutic agents are optionally administered in any orderor even simultaneously. If simultaneously, the therapeutic agents areoptionally provided in a single, unified form, or in multiple forms (byway of example only, either as a single pill or as two separate pills).In certain instances, one of the therapeutic agents is optionally givenin multiple doses. In other instances, both are optionally given asmultiple doses. If not simultaneous, the timing between the multipledoses is any suitable timing, e.g, from more than zero weeks to lessthan four weeks. In addition, the combination methods, compositions andformulations are not to be limited to the use of only two agents; theuse of multiple therapeutic combinations are also envisioned (includingtwo or more compounds described herein).

In certain embodiments, a dosage regimen to treat, prevent, orameliorate the condition(s) for which relief is sought, is modified inaccordance with a variety of factors. These factors include the disorderfrom which the subject suffers, as well as the age, weight, sex, diet,and medical condition of the subject. Thus, in various embodiments, thedosage regimen actually employed varies and deviates from the dosageregimens set forth herein.

In some embodiments, the pharmaceutical agents which make up thecombination therapy described herein are provided in a combined dosageform or in separate dosage forms intended for substantially simultaneousadministration. In certain embodiments, the pharmaceutical agents thatmake up the combination therapy are administered sequentially, witheither therapeutic compound being administered by a regimen calling fortwo-step administration. In some embodiments, two-step administrationregimen calls for sequential administration of the active agents orspaced-apart administration of the separate active agents. In certainembodiments, the time period between the multiple administration stepsvaries, by way of non-limiting example, from a few minutes to severalhours, depending upon the properties of each pharmaceutical agent, suchas potency, solubility, bioavailability, plasma half-life and kineticprofile of the pharmaceutical agent.

In some embodiments, the methods herein comprise administration of acomposition described herein and a physical activity regimen. Thephysical activity regimen can be an exercise regimen. The physicalactivity regimen can be recommended to the subject by, e.g., acaregiver, or can be undertaken by the subject under the subject's owninitiative. The physical activity regimen can comprise one or moreepisodes or bouts of any kind of physical activity or exercise,including, by way of example only, walking, power walking, hiking,backpacking, running, jogging, freerunning, parkour, biking, swimming,strolling, treadmilling, spinning, rowing, yoga, zumba, weightlifting,dancing, gymnastics, martial arts, track and field activities, athleticactivity, sports such as, e.g., football, baseball, softball, cricket,kickball, dodgeball, soccer, basketball, hockey, ice skating,rollerskating, rollerblading, skateboarding, surfing, bowling, skiing,polo, water polo, lacrosse, snowboarding, rugby, wrestling, boxing,aerobatics, archery, fencing, badminton, tennis, table tennis, squash,diving, Frisbee, Ultimate Frisbee, climbing, e.g., rock climbing,billiards, horseback riding, golf, orienteering, circus arts such as,e.g., trampolining, trapeze, contortion, juggling, aerial fabrics, andthe like. An episode or bout of physical activity can be undertaken fora length of time, e.g., 1-10 minutes, 5-20 minutes, 15-30 minutes, 30-60minutes (1 hours), 2 hours, 4 hours, 8 hours, 12 hours, 24 hours, ormore than 24 hours. A bout of physical activity can be less than 30minutes. The subject can engage in one bout of physical activity permonth, per week, 2 bouts per week, 3 bouts per week or more, one bout ofactivity a day, twice a day, or more than twice a day. The physicalactivity regimen can comprise, by way of example only, 1 bout ofphysical activity per day, wherein a bout of physical activity is for,e.g., 20 minutes. Administration of a composition as described herein incombination with a physical activity regimen can have synergisticbeneficial effects on the subject, e.g., synergistic therapeuticeffects.

The administration of a composition described herein, such as acombination composition, to a subject can allow for the regulation ormaintenance of the subject's energy metabolism. The regulation ormaintenance of energy metabolism can allow for a subject to experience anumber of beneficial effects. These beneficial effects include areduction in weight, a reduction in adipose tissue, an increase in fattyacid oxidation, an increase in insulin sensitivity, a decrease inoxidative stress, and/or a decrease in inflammation. Compared to abaseline prior to treatment, these effects can result in an improvementof about or greater than about 5, 10, 15, 20, 30, 40, 50, 75, 100, 125,150, 200, 250, 300, 400, or 500%. Alternatively, administration of acomposition described herein can allow for maintenance of the subject'sweight, amount of adipose tissue, amount of fatty acid oxidation, levelof insulin sensitivity, oxidative stress level, and/or level ofinflammation. These amounts and/or levels can be maintained within 0, 1,5, or 10% of the amounts and/or levels at the initiation ofadministration.

Another aspect of the invention provides for achieving desired effectsin one or more subjects after administration of a combinationcomposition described herein for a specified time period.

After a period of 6 weeks of administration of the composition, acombination composition comprising (a) a dosing level of a PDE 5inhibitor and a dosing level of HMB or (b) a dosing level of a PDEinhibitor, e.g., a PDE 5 inhibitor and a dosing level of leucine (e.g.,free leucine), can reduce weight gain in the one or more subjects by atleast about 10, 15, 20, or 20.5%. The p-value can be less than 0.05(e.g. less than about 0.05, 0.03, 0.02, 0.01, 0.001, 0.0001, or lower).The one or more subjects treated with the same dosing level of one ofthe components (sildenafil, icariin, resveratrol, leucine, or HMB) mayhave insignificant weight reduction, or a weight reduction that is lessthan about 0, 5, or 10%.

After a period of 2 weeks of administration, a composition comprising(a) a dosing level of PDE inhibitor, e.g., a PDE 5 inhibitor and adosing level of HMB or (b) a dosing level of resveratrol and a dosinglevel of leucine (e.g., free leucine), can increase whole body fatoxidation in the one or more subjects by at least about 10, 15, or 20%.The p-value can be less than 0.05 (e.g. less than about 0.05, 0.03,0.02, 0.01, 0.001, 0.0001, or lower). The increase in whole body fatoxidation can be sustained while the subjects are administered thecomposition, or for a period of at least 2, 4, 6, 10, 13, 26, or 52weeks. The one or more subjects treated with the same dosing level ofone of the components (sildenafil, icariin, resveratrol, leucine, orHMB) may have insignificant increase in whole body fat oxidation, or anincrease in whole body fat oxidation that is less than about 0, 5, or10%.

After a period of 2 weeks of administration, a composition comprising(a) a dosing level of a PDE inhibitor, e.g., a PDE 5 inhibitor and adosing level of HMB or (b) a dosing level of resveratrol and a dosinglevel of leucine (e.g., free leucine), can increase the thermic effectof food in the one or more subjects by at least about 10, 15, 17, or20%. The p-value can be less than 0.05 (e.g. less than about 0.05, 0.03,0.02, 0.01, 0.001, 0.0001, or lower). The increase in the thermic effectof food can be sustained while the subjects are administered thecomposition, or for a period of at least 2, 4, 6, 10, 13, 26, or 52weeks. The one or more subjects treated with the same dosing level ofone of the components (sildenafil, icariin, resveratrol, leucine, orHMB) may have insignificant increase the thermic effect of food, or anincrease the thermic effect of food that is less than about 0, 5, or10%.

After a period of 2 weeks of administration, a composition comprising(a) a dosing level of a PDE inhibitor, e.g., a PDE 5 inhibitor and adosing level of HMB or (b) a dosing level of a PDE inhibitor, e.g., aPDE 5 inhibitor and a dosing level of leucine (e.g., free leucine), canincrease total energy expenditure in the one or more subjects by atleast about 10, 15, 17, or 20%. The p-value can be less than 0.05 (e.g.less than about 0.05, 0.03, 0.02, 0.01, 0.001, 0.0001, or lower). Theincrease total energy expenditure can be sustained while the subjectsare administered the composition, or for a period of at least 2, 4, 6,10, 13, 26, or 52 weeks. The one or more subjects treated with the samedosing level of one of the components (sildenafil, icariin, resveratrol,leucine, or HMB) may have insignificant increase total energyexpenditure, or an increase total energy expenditure that is less thanabout 0, 5, or 10%.

The administration of a composition described herein, such as acombination composition, to a subject can allow for the regulation ormaintenance of the subject's energy metabolism. The regulation ormaintenance of energy metabolism can allow for a subject to experience anumber of beneficial effects. These beneficial effects include areduction in weight, a reduction in adipose tissue, an increase in fattyacid oxidation, an increase in browning of adipose tissue (as indicatedby one or more indicia of fat cell browning), an increase in insulinsensitivity, a decrease in oxidative stress, and/or a decrease ininflammation. Compared to a baseline prior to treatment, these effectscan result in an improvement of about or greater than about 5%, 10%,15%, 20%, 30%, 40%, 50%, 75%, or more. In some embodiments, compared toa baseline prior to treatment, these effects can result in animprovement of about or greater than about 100%, 125%, 150%, 200%, 250%,300%, 400%, 500%, or more. Alternatively, administration of acomposition described herein can allow for maintenance of the subject'sweight, amount of adipose tissue, amount of fatty acid oxidation, levelof insulin sensitivity, oxidative stress level, and/or level ofinflammation. These amounts and/or levels can be maintained within about0%, 1%, 5%, or 10% of the amounts and/or levels at the initiation ofadministration.

The invention provides for a method of treating subjects, comprisingidentifying a pool of subjects amenable to treatment. The identifyingstep can include one or more screening tests or assays. For example,subjects that are identified as diabetic, as having insulin resistance,or that have above average or significantly greater than average bodymass indices and/or weight can be selected for treatment. Theidentifying step can include a genetic test that identifies one or moregenetic variants that suggest that the subject is amenable to treatment.The identified subjects can then be treated with one or morecompositions described herein. In one embodiment, the invention providesa method of regulating energy metabolism comprising: (a) identifying asubject having or prone to obesity or diabetes; and (b) administering tothe subject a composition described herein, for example any compositionof originally filed claims 1-29. For example, they may be treated with acombination composition comprising a selective PDE inhibitor, such as aPDE 5 inhibitor, and a branched-chain amino acid.

The invention also provides for methods of manufacturing thecompositions described herein. In some embodiments, the manufacture of acomposition described herein comprises mixing or combining two or morecomponents. These components can include a selective PDE inhibitor,including but not limited to PDE 5 inhibitor in combination with leucine(e.g., free leucine) and/or leucine metabolites. The composition canfurther include additional a sirtuin or AMPK pathway activator (such asa polyphenol or polyphenol precursor like resveratrol, chlorogenic acid,caffeic acid, cinnamic acid, ferulic acid, EGCG, piceatannol, or grapeseed extract, or another agent like quinic acid and fucoxanthin. In someembodiments, the sirtuin activator is a polyphenol. In otherembodiments, the sirtuin activator is a polyphenol precursor. The amountor ratio of components can be that as described herein.

In some embodiments, the compositions can be combined or mixed with apharmaceutically active agent other than a PDE-5 inhibitor, a carrier,and/or an excipient. Examples of such components are described herein.The combined compositions can be formed into a unit dosage as tablets,capsules, gel capsules, slow-release tablets, or the like.

In some embodiments, the composition is prepared such that a solidcomposition containing a substantially homogeneous mixture of the one ormore components is achieved, such that the one or more components aredispersed evenly throughout the composition so that the composition maybe readily subdivided into equally effective unit dosage forms such astablets, pills and capsules.

Kits

The invention also provides kits. The kits include one or morecompositions described herein, in suitable packaging, and writtenmaterial that can include instructions for use, discussion of clinicalstudies, listing of side effects, and the like. Such kits may alsoinclude information, such as scientific literature references, packageinsert materials, clinical trial results, and/or summaries of these andthe like, which indicate or establish the activities and/or advantagesof the composition, and/or which describe dosing, administration, sideeffects, drug interactions, or other information useful to the healthcare provider. Such information may be based on the results of variousstudies, for example, studies using experimental animals involving invivo models and studies based on human clinical trials. The kit mayfurther contain another agent. In some embodiments, the compound of thepresent invention and the agent are provided as separate compositions inseparate containers within the kit. In some embodiments, the compound ofthe present invention and the agent are provided as a single compositionwithin a container in the kit. Suitable packaging and additionalarticles for use (e.g., measuring cup for liquid preparations, foilwrapping to minimize exposure to air, and the like) are known in the artand may be included in the kit. Kits described herein can be provided,marketed and/or promoted to health providers, including physicians,nurses, pharmacists, formulary officials, and the like. Kits may also,in some embodiments, be marketed directly to the consumer.

In some embodiments, a kit can comprise a multi-day supply of unitdosages. The unit dosages can be any unit dosage described herein. Thekit can comprise instructions directing the administration of themulti-day supply of unit dosages over a period of multiple days. Themulti-day supply can be a one-month supply, a 30-day supply, or amulti-week supply. The multi-day supply can be a 90-day, 180-day,3-month or 6-month supply. The kit can include packaged daily unitdosages, such as packages of 1, 2, 3, 4, or 5 unit dosages. The kit canbe packaged with other dietary supplements, vitamins, and mealreplacement bars, mixes, and beverages.

In some embodiments, a kit can further comprise a wearable activitymonitor. The wearable activity monitor can monitor physical and/orambulatory activity via a pedometer, accelerometer, or Exemplarywearable activity monitors include, e.g.; a Fitbit®, Jawbone UP®,LarkLife™, Nike FuelBand, Striiv Play, BodyMedia FitCore, among others.Such wearable activity monitors are described in U.S. Pat. Nos.8,403,845; 8,398,546; 8,382,590; 8,369,936; 8,275,635; 8,157,731;8,073,707; 7,959,567; 7,689,437; 7,502,643; 7,285,090; 7,261,690;7,153,262; 7,020,508; 6,605,038; 6,595,929; 6,527,711; 8,562,489;8,517,896; 8,469,862; 8,408,436; 8,370,549; 8,088,044; 8,088,043, and USPatent Application Publication Nos. 20130158369 and 20130151196, all ofwhich are hereby incorporated by reference. Such kits can furthercomprise instructions for the subject to engage in a physical activityregimen in addition to instructions for use of the composition. Suchkits can further comprise instructions for use of the wearable activitymonitors. Such kits can also comprise wearable activity monitoraccessories, such as, e.g., a charger, and/or a port or wireless forcommunicating data from the activity monitor to a computer or server.

EXAMPLES Example 1—PDE 1 Inhibitors for Regulating Energy Metabolism

Vinopocetine, which is a PDE 1 inhibitor, was tested in combination withleucine, HMB, and resveratrol for its effects on energy metabolism.Dose-response indicates that concentrations of 0.1 nM or below ofvinopocetine exert no effect; accordingly, this was the concentrationused in these experiments. Vinpocetine exhibited no synergy with eitherleucine (0.5 mM) or HMB (5 μM) with respect to either fat oxidation orglucose utilization, although it did exhibit a synergistic effect withlow-dose resveratrol 200 nM), resulting in a 70% increase in glucoseutilization in adipocytes (p=0.03).

Example 2—PDE 3 Inhibitors for Regulating Energy Metabolism

Two PDE 3 inhibitors were studied, amrinone and cilostamide, incombination with leucine and HMB for their effects on energy metabolism.Dose-response indicates that concentrations of 10 nM or below for eitherPDE 3 inhibitor exert no effect; accordingly, this concentration for thePDE 3 inhibitors was used in these experiments. Amrinone exerted nosignificant synergy with either leucine or HMB. However, combiningeither leucine (0.5 mM) or HMB (5 μM) with cilostamide resulted in a 92%increase in fat oxidation (p<0.05) in muscle cells and a 58% increase inadipocytes (p<0.05). The cilostamide-HMB blend synergistically increasedglucose utilization by 202% in muscle cells (p=0.024) and by 83% inadipocytes (p=0.05), while the cilostamide-leucine blend exerted noeffect.

Example 3—PDE 4 Inhibitors for Regulating Energy Metabolism

Two PDE 4 inhibitors were studied, rolipram and YM796, in combinationwith leucine and HMB for their effects on energy metabolism.Dose-response indicate concentrations of 0.1 nM or below of rolipram andYM796 exert no effect; accordingly, this was the concentration used inthese experiments. There was no synergistic effect of rolipram withleucine, HMB or resveratrol with respect to fat oxidation, glucoseutilization or AMPK activity in muscle cells; although rolipramactivated AMPK phosphorylation, this effect was not augmented by thepresence of either leucine or HMB. However, fat oxidation synergy wasevident in adipocytes, with a 125% increase in fat oxidation in responseto the rolipram-leucine combination (p=0.026) and a 63% increase inresponse to the rolipram-HMB combination. However, no synergy was foundfor glucose utilization or AMPK activation.

Example 4—PDE 5 Inhibitors for Regulating Energy Metabolism

Cells were treated with combinations of sildenafil (1 nM), icariin (1nM), leucine (0.5 mM), HMB (5 μM), and resveratrol (200 nM). Treatmentwith 0.5 mM leucine corresponds to a circulating level of the samemolarity achieved by administering about 1,125 mg of dietary leucine toa human subject. Treatment with 0.25 mM leucine corresponds to acirculating level of the same molarity achieved by administering about300 mg of dietary leucine to a human subject. Treatment with 1 nMsildenafil corresponds to a circulating level of the same molarityachieved by administering about 0.2 mg of dietary sildenafil to a humansubject. Treatment with 1 nM sildenafil corresponds to a circulatinglevel of the same molarity achieved by administering about 0.1 mg ofdietary sildenafil to a human subject.

Sildenafil dose-response curves indicate concentrations below 1 nM exertno effect; accordingly, this was the concentration used in synergyexperiments. This is approximately 1% of the peak plasma concentration(˜100 nM) achieved in response to a low dose of the drug (20 mg).Treatment of C2C12 myotubes with Sildenafil alone resulted in a fattyacid oxidation change from baseline of about 50%. Treatment with leucinealone stimulates fatty acid oxidation to 73%, p<0.05. Sildenafil at thisconcentration exerted a significant synergy in stimulating myotube fatoxidation with both HMB (203% increase, p=0.003) and leucine (232%increase, p=0.015), but exhibited no interaction with resveratrol inmuscle cells (FIG. 2 and FIG. 3).

In 3T3-L1 adipocytes, treatment with leucine increases fatty acidoxidation to 27%, p<0.05 and treatment with HMB stimulates fatty acidoxidation to 29%, p<0.05. As with C2C12 cells, sildenafil-leucine andsildenafil-HMB synergistically increased fat oxidation in adipocytes by137% and 240%, respectively (p<0.05; FIG. 4). Addition of resveratrol(200 nM) to either the sildenafil-leucine or sildenafil-HMB exerted noadditional effect and was not significantly different from thesemixtures in the absence of resveratrol.

Sildenafil also exhibited synergy with leucine and HMB in stimulatingglucose utilization in both myotubes and adipocytes. Treatment of C2C12myotubes with leucine alone increases glucose utilization to 9.3%.Sildenafil-leucine and sildenafil-HMB synergistically augmented myotubeglucose utilization by 53 and 66%, respectively (p=0.04, FIG. 5), andsildenafil also exhibited synergy with resveratrol to produce a similaraugmentation (53%, p=0.04). Treatment with leucine stimulates glucoseutilization in 3T3-L1 cells to 48.6%, p<0.05. In 3T3-L1 adipocytes,sildenafil-leucine increased glucose utilization by 285% (p=0.05, FIG.6), while neither HMB nor resveratrol exerted any significant synergywith sildenafil.

Icariin is a naturally occurring flavonol with significant PDE 5inhibitory activity. Dose-response curves indicate icariinconcentrations below 1 nM exert no effect; accordingly, this was theconcentration used in synergy experiments. Treatment of C2C12 myotubeswith leucine alone stimulates fatty acid oxidation to 73%, p<0.05.Icariin at this concentration exerted a significant synergy instimulating C2C12 myotube fat oxidation with both HMB (75% increase) andleucine (77% increase) (p=0.03, FIG. 7 and FIG. 8), while resveratrolexerted an independent synergistic effect (157% increase, p=0.002, FIG.8). Similar data were obtained in adipocytes (p<0.05; FIG. 9); however,icariin did not exhibit significant synergy with respect to glucoseutilization.

There were significant synergistic interactions between both sildenafiland icariin with leucine, HMB, resveratrol, and combinations thereof onnitric oxide production. FIG. 10 shows the interaction betweensildenafil and leucine, HMB and resveratrol, and FIG. 11 shows theinteraction between icariin and leucine, HMB and resveratrol. Leucine,HMB and resveratrol each interacted with low dose sildenafil (1 nM) toproduce modest, significant increases in nitric oxide production (15-30%increases, p<0.0001), while the combination of sildenafil, leucine andresveratrol produced a more robust response (52% increase, p=0.0003 vs.all other treatments, FIG. 10). Similar effects were noted with icariin,with leucine, HMB and resveratrol each interacting to elicit modest,significant effects (p<0.0001), with a more robust effect found with thecombination of sildenafil, leucine and resveratrol (FIG. 11; p=0.00013).

Nitric oxide has been demonstrated to regulate PGC1α and therebystimulate mitochondrial biogenesis; accordingly, we evaluated theeffects of sildenafil and icariin combinations with leucine, HMB andresveratrol on mitochondrial biogenesis, as measured mitochondrialbiomass. C2C12 cells treated with leucine alone have a mitochondrialbiomass of 22.05+/−0.4 AFU/μg protein, p<0.05, FIG. 12 demonstrates asignificant synergy between sildenafil (1 nM) and either leucine or HMB,as leucine-sildenafil and leucine-HMB each stimulated significantincreases in mitochondrial biomass (p<0.01), while there was nosignificant effect of resveratrol on this interaction. Similarly,icariin exhibited a significant synergy with both leucine and HMB to upregulate mitochondrial biogenesis (p<0.001), while resveratrol did notexhibit a significant interaction (FIG. 13).

The observed synergy between leucine/HMB and sildenafil in augmentingoxidative metabolism is non-obvious, as a recent report indicates that aclosely related member of this drug class, Tadalafil (trade name Cialis)has been reported to suppress aerobic metabolism in the same cell system(C2C12 myotubes). However, chronic (12-week) administration ofsildenafil resulted in increased energy expenditure, reduced weight andfat gain, and increased insulin sensitivity, although acuteadministration was without effect. Our data suggest that combiningsubstantially lower concentrations than those used for treatment oferectile dysfunction with either leucine or HMB will be a usefultherapeutic strategy for diabetes management. As an alternative tosildenafil, icariin is a naturally occurring flavonol found in plants ofthe Epimedium family (horny goat weed) which also has PDE5 inhibitoryactivity and exerts similar effects.

Example 5—In Vivo Effect of PDE 5 Inhibitors on Glycemia and InsulinSensitivity

The interactive effects of icariin, a flavanol with specific PDE5inhibitory properties, on glycemia and insulin sensitivity were assessedin the diet-induced obese mouse, which can be used as a murine model oftype 2 diabetes.

Methods

Male C57/BL6 mice were placed on standard low-fat chow (control; 10%energy from fat) or high fat (60% energy from fat, Research Diets#D12492, Research Diets, Inc, New Brunswick, N.J.) at six weeks of ageto induce insulin resistance. The mice on the high fat diet exhibitedimpaired glucose tolerance after 6 weeks of exposure, as compared to lowfat diet mice (see FIG. 14).

The animals were then randomized to the following diets for anadditional six weeks, with 10 animals per group: Low fat diet (LFD)control; High fat diet (HFD) control; HFD+leucine (24 g/kg diet, atwo-fold increase over control levels) 1 HFD+leucine (24 g/kgdiet)+icariin (25 mg/kg diet). Previous published studies of icariinhave demonstrated no effect of the selected level (25 mg/kg diet; ˜4mg/kg body weight).

Mice were fasted overnight (˜16 hours) prior to measurement of fastingblood glucose, insulin and glucose tolerance. Glucose tolerance wasdetermined following measurement of fasting glucose via intraperitonealadministration of glucose (1.2 g/kg body weight) followed by bloodglucose measurement at 15, 30, 60, 90 and 120 minutes. Post-prandialglucose was measured within one hour of cessation of eating. Insulintolerance was measured via an insulin tolerance test (ITT). Food wasremoved 4-6 hours prior to ITT, and baseline blood glucose measured. Themice were then injected intraperitoneally with insulin (1.2 U/kg bodyweight) and blood glucose was measured 15, 30, 60, 90 and 120 minutesfollowing insulin injection. The homeostasis model assessment of insulinresistance (HOMA_(IR)) was used as a screening index of changes ininsulin sensitivity. HOMA_(IR) is calculated via standard formula

from fasting plasma insulin and glucose as follows: HOMA_(IR)=[Insulin(uU/mL)×glucose (mM)]/22.5. The plasma glucose and insulinconcentrations were measured using the Glucose Assay Kit from Biovision(Milpitas, Calif.) and the Insulin kit from Millipore (Billerica,Mass.), respectively. CRP levels in plasma were determined by ELISA(CRP: Life Diagnostics, West Chester, Pa.).

Data were analyzed via one-way analysis of variance; when ANOVA showedsignificant differences, means were separated via Tukey's multiplecomparison test (Graphpad Prism, Version 6.0). p-values of less than0.05 are generally considered statistically significant.

Results

Post-prandial glucose was markedly elevated in response to the high fatdiet by day 7 of treatment (FIG. 15). Although leucine exerted noindependent effect on glucose, the combination of leucine and icariincaused a significant reduction of about 10% in post-prandial glucoseafter 7 day of treatment as compared to untreated HFD mice (p<0.01 vs.HFD, FIG. 15). This effect increased in magnitude after 14 days to about20%, such that the leucine-icariin combination treatment in HFD micereduced post-prandial glucose to levels found in the low-fat diet mice(p<0.001 vs. HFD, FIG. 16).

Post-prandial insulin, or circulating insulin, levels were measured inall experimental groups following 14 days of treatment. HFD miceexhibited a ˜5-fold elevation in circulating insulin as compared to theLFD mice (FIG. 17). However, 14-day treatment of HFD mice with insulinalone decreased circulating insulin by ˜30% as compared to untreated HFDmice (FIG. 17). 14-day treatment of HFD mice with leucine and icariinfurther decreased circulating insulin levels by about 50% as compared tountreated HFD mice (p<0.01 vs. HFD, FIG. 17).

Insulin sensitivity was measured via Homeostatic Assessment of InsulinResistance (HOMA_(IR)) in all experimental groups following 14 days oftreatment. (HOMA_(IR)=insulin (uU/mL)×glucose (mM)/22.5). HFD miceexhibited a 10-fold elevation in HOMA_(IR) as compared to LFD mice (FIG.18). However, 14-day treatment of HFD mice with insulin alone decreasedHOMA_(IR) by ˜40% as compared to untreated HFD mice (p<0.001 vs. HFD,FIG. 18). 14-day treatment of HFD mice with leucine and icariin furtherdecreased HOMA_(IR) levels by about 65% as compared to untreated HFDmice (p<0.001 vs. all, FIG. 18).

Insulin sensitivity was measured via insulin tolerance testing in allexperimental groups following 28 days of treatment. As shown in FIG. 19,the addition of leucine and icariin to the high fat diet improved theresponse to insulin to a level that matched that found in the low fatdiet. Since the maximum decrease in blood glucose was found at 30minutes, statistical analysis was performed on the change in bloodglucose at 30 minutes (FIG. 20). Analysis of the insulin tolerance test30 minute time point shows that glucose clearance in HFD mice wasreduced by about 50% as compared to LFD mice (FIG. 20). However,treatment of HFD mice with leucine and icariin fully rescued glucoseclearance to levels found in the LFD mice, a two-fold change relative toHFD mice not treated with leucine and icariin (p<0.02 vs. HFD, FIG. 20).This analysis shows that the blunted response to insulin caused by thehigh fat diet was fully reversed by the addition of the leucine-icariincombination.

Glucose tolerance was assessed in all experimental groups after fiveweeks of treatment. FIG. 21 depicts results from the glucose tolerancetest measured at five weeks of treatment and demonstrates significantreduction in the blood glucose response to the glucose challenge. Areaunder the curve (AUC) measures were performed on the glucoseconcentration curves of FIG. 21 to obtain a measure of integratedglucose response to glucose load over time. AUC was increased by ˜75% ascompared to LFD mice (p<0.01, FIG. 22). Treatment of the HFD mice withleucine and icariin significantly decreased glucose load by about 40% ascompared to untreated HFD mice (p<0.01 vs. HFD mice, FIG. 22).

At the end of the 6 week study, fasting blood glucose levels, insulinlevels, HOMA_(IR), liver mass, and circulating C-reactive protein (abiomarker of inflammation) were assessed in all experimental groups(FIG. 23-27). Assessment of fasting blood glucose at the end of the 6week study revealed that HFD mice exhibited a ˜1-fold increase infasting glucose as compared to LFD mice (FIG. 23). 6 week treatment ofthe HFD mice with leucine alone reduced fasting glucose by ˜20% ascompared to untreated HFD mice (FIG. 23). 6 week treatment of the HFDmice with leucine+icariin reduced fasting glucose by about 40% ascompared to untreated HFD mice (p=0.0014 vs. HFD, FIG. 23). Assessmentof fasting insulin levels at the end of the 6 week study revealed thatHFD mice exhibited an 8-fold increase in circulating insulin as comparedto LFD mice (FIG. 24). 6 week treatment of the HFD mice with leucinealone reduced circulating insulin during fasting by ˜25% as compared tountreated HFD mice (FIG. 24). 6 week treatment of the HFD mice withleucine+icariin reduced circulating insulin during fasting by about 40%as compared to untreated HFD mice (p<0.05 vs. HFD, FIG. 24). Assessmentof HOMA_(IR) at the end of the 6 week study revealed that HFD miceexhibited a ˜10-fold increase in circulating insulin as compared to LFDmice (FIG. 25). 6 week treatment of the HFD mice with leucine alonereduced HOMA_(IR) by ˜30% as compared to untreated HFD mice (FIG. 25). 6week treatment of the HFD mice with leucine+icariin reduced HOMA_(IR) byabout 45% as compared to untreated HFD mice (p<0.03 vs. HFD, FIG. 25).These results demonstrated that combined administration of a branchedamino acid (e.g., free leucine) and a PDE5 inhibitor remaintherapeutically effective against diabetes for a long term, withoutlosing effectiveness even after 6 weeks of administration in mice.Taking into account the life expectancy of laboratory mice vs. lifeexpectancy of an average human, this effectiveness in mice suggests thatthe combined administration of a branched amino acid (e.g., freeleucine) and a PDE5 inhibitor can remain therapeutically effective(e.g., against diabetes) for four years or more.

A chronic high fat diet is associated with other deleteriousconsequences. For example, a chronic high fat diet can increase livermass, likely resulting from fatty accumulation in the liver. Chronichigh fat feeding is also associated with chronic inflammation, which cancontribute to a number of diseases. To determine the effects of leucineor leucine+icariin administration on additional consequences of high fatfeeding, liver mass and C-reactive protein (a biomarker of inflammation)were assessed in all experimental groups at the end of the 6 week study.Assessment of liver mass at the end of the 6 week study revealed thatHFD mice exhibited a ˜40% increase in liver mass as compared to LFD mice(p=0.01, FIG. 26). 6 week treatment of the HFD mice with leucine alonereduced liver mass by ˜10% as compared to untreated HFD mice (FIG. 26).6 week treatment of the HFD mice with leucine+icariin reduced liver massby about 25% as compared to untreated HFD mice (p<0.01 vs. HFD, FIG.26). Assessment of c-reactive protein at the end of the 6 week studyrevealed that HFD mice exhibited a ˜30% increase in liver mass ascompared to LFD mice (FIG. 27). 6 week treatment of the HFD mice withleucine+icariin reduced C-reactive protein levels by about 20% ascompared to untreated HFD mice (p<0.05 vs. HFD, FIG. 27).

All together, these data demonstrate significant, robust improvements infasting and post-prandial glucose, glucose tolerance and insulinsensitivity in response to a low dose of icariin in combination withleucine. These improvements are comparable to those of anti-diabeticpharmaceuticals in this animal model, indicating the therapeuticpotential of this combination. Moreover, this combination resulted in asignificant improvement in liver mass and the inflammatory biomarkerc-reactive protein.

It should be understood from the foregoing that, while particularimplementations have been illustrated and described, variousmodifications can be made thereto and are contemplated herein. It isalso not intended that the invention be limited by the specific examplesprovided within the specification. While the invention has beendescribed with reference to the aforementioned specification, thedescriptions and illustrations of the preferable embodiments herein arenot meant to be construed in a limiting sense. Furthermore, it shall beunderstood that all aspects of the invention are not limited to thespecific depictions, configurations or relative proportions set forthherein which depend upon a variety of conditions and variables. Variousmodifications in form and detail of the embodiments of the inventionwill be apparent to a person skilled in the art. It is thereforecontemplated that the invention shall also cover any such modifications,variations and equivalents.

What is claimed is:
 1. A composition comprising: (a) a synergisticallyeffective amount of a phosphodiesterase 5 (PDE 5) inhibitor; and (b) atleast 500 mg of leucine and/or at least 200 mg of a leucine metabolite,wherein the PDE 5 inhibitor comprises sildenafil.
 2. The composition ofclaim 1, wherein the amount of phosphodiesterase 5 (PDE 5) inhibitor isa sub-therapeutic amount.
 3. The composition of claim 1, wherein thecomposition is formulated as a unit dosage.
 4. The composition of claim3, wherein the unit dosage comprises a sub-therapeutic amount ofcomponent (a) that is between 0.1 and 20 mg of sildenafil.
 5. Thecomposition of claim 3, wherein the unit dosage comprises asub-therapeutic amount of component (a) that is between 0.1 and 10 mg ofsildenafil.
 6. The composition of claim 2, wherein the sub-therapeuticamount of component (a) further comprises between 0.5-50 mg of avanafil,0.05-10 mg of iodenafil, 0.25-25 mg of mirodenafil, 0.01-1.25 mg oftadalafil, 0.01-1.25 mg of vardenafil, 0.5-50 mg of udenafil, 0.5-50 mgof zaprinst, or 0.05-100 mg of icariin.
 7. The composition of claim 1,wherein the component (b) is free leucine.
 8. The composition of claim1, wherein the component (b) comprises between 500 to 2000 mg of freeleucine.
 9. The composition of claim 1, wherein the component (b)comprises at least 200 mg of a leucine metabolite comprisingbeta-hydroxymethylbutyrate (HMB).
 10. The composition of claim 1,further comprising an anti-diabetic agent.
 11. The composition of claim1, further comprising a sub-therapeutic amount of an anti-diabeticagent.
 12. The composition of claim 10, wherein the anti-diabetic agentis a biguanide or thiazoladinedione.
 13. The composition of claim 10,wherein the anti-diabetic agent is metformin or rosiglitazone.
 14. Thecomposition of claim 10, wherein the anti-diabetic agent comprises atleast 25 mg of metformin.
 15. The composition of claim 1, furthercomprising resveratrol.
 16. The composition of claim 10, whereincomponent (a) comprises between 0.1 and 10 mg of sildenafil, component(b) comprises between 500 and 2000 mg of free leucine, and theanti-diabetic agent comprises at least 250 mg of metformin.
 17. Thecomposition of claim 1, further comprising a pharmaceutically activeagent other than the PDE 5 inhibitor and the leucine and/or the leucinemetabolite.
 18. The composition of claim 1, wherein the compositionfurther comprises less than 1% by weight of an amino acid selected fromthe group consisting of alanine, arginine, asparagine, aspartic acid,cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine,lysine, methionine, phenylalanine, proline, serine, threonine,tryptophan, tyrosine, and valine in free amino acid form.
 19. Thecomposition of claim 1, wherein the composition further comprises lessthan 1% by weight of isoleucine and valine.
 20. The composition of claim1, wherein the composition is free of isoleucine and valine.
 21. Thecomposition of claim 1, wherein the composition is formulated in tabletsor capsules.